There are 429 accepted posters for TQC 2024. Of these, the Programme Committee highlighted 19 Outstanding Posters: you can find them by filtering on the dropdown tag menu below.
Clarifications
Accepted does not mean presented: Note that not all accepted posters will be presented at the conference due to author availability constraints. Shortly before the conference start, we will clarify which posters are set to be presented in person, based on whether the authors have registered for the conference. If you are interested in a particular poster, please contact the author directly.
Online presentation: For authors who cannot make it to the conference, it will be possible to present the poster online throughout the week on our Discord server. We will share instructions closer to the conference. In our experience, online attendance of these presentations is much lower than in-person attendance.
Withdrawing poster: If you cannot or do not wish to present your accepted poster, you don’t need to contact the organizers or PC chairs; this list will stay here to mark all submissions that were accepted. Exception: if you found a fatal mistake in the submission or would like to change the authors’ names, please let us know.
Upload media: If you would like to upload a thumbnail, more links or the poster pdf, please follow the link on the notification email sent by the PC chairs to the corresponding authors.
Poster sessions: The live poster sessions will be on Monday and Thursday (see schedule). If your poster submission number is below 290, you present on Monday; if it is above 290, you present on Thursday (290 is a talk). If you cannot make it to your allocated session, just bring the poster to the other session and find a free slot. You don’t need to ask the organizers.
Poster printing and size: The poster size should be A0 (84.1 cm × 118.9 cm) in portrait orientation. We recommend bringing your poster with you, as printing options in Okinawa are limited.
1.
Daniel Bonior
A Domain of Symmetric Unital Channels Poster
2024.
Tags: Poster session Monday
@Poster{P24_186,
title = {A Domain of Symmetric Unital Channels},
author = {Daniel Bonior},
year = {2024},
date = {2024-01-01},
keywords = {Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
2.
Robert Booth, Titouan Carette, Cole Comfort
A graphical language for Gaussian quantum processes Poster
2024.
Tags: Poster session Monday
@Poster{P24_127,
title = {A graphical language for Gaussian quantum processes},
author = {Robert Booth and Titouan Carette and Cole Comfort},
year = {2024},
date = {2024-01-01},
keywords = {Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
3.
Andi Gu, Lorenzo Leone, Soumik Ghosh, Jens Eisert, Susanne Yelin, Yihui Quek
A little magic means a lot Poster
2024.
Abstract | Tags: Poster session Monday | Links:
@Poster{P24_260,
title = {A little magic means a lot},
author = {Andi Gu and Lorenzo Leone and Soumik Ghosh and Jens Eisert and Susanne Yelin and Yihui Quek},
url = {https://arxiv.org/abs/2308.16228},
year = {2024},
date = {2024-01-01},
abstract = {Notions of nonstabilizerness, or ``magic'', quantify how non-classical quantum states are in a precise sense: states exhibiting low nonstabilizerness preclude quantum advantage. We introduce `pseudomagic' ensembles of quantum states that, despite low nonstabilizerness, are computationally indistinguishable from those with high nonstabilizerness. Previously, such computational indistinguishability has been studied with respect to entanglement, introducing the concept of pseudoentanglement. However, we demonstrate that pseudomagic neither follows from pseudoentanglement nor implies it. In terms of applications, the study of pseudomagic offers fresh insights into the theory of quantum scrambling: it uncovers states that, even though they originate from non-scrambling unitaries, remain indistinguishable from scrambled states to any physical observer. Additional applications include new lower bounds on state synthesis problems, property testing protocols, and implications for quantum cryptography. Our work is driven by the observation that only quantities measurable by a computationally bounded observer – intrinsically limited by finite-time computational constraints – hold physical significance. Ultimately, our findings suggest that nonstabilizerness is a `hide-able' characteristic of quantum states: some states are much more magical than is apparent to a computationally bounded observer.},
keywords = {Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
Notions of nonstabilizerness, or ``magic'', quantify how non-classical quantum states are in a precise sense: states exhibiting low nonstabilizerness preclude quantum advantage. We introduce `pseudomagic' ensembles of quantum states that, despite low nonstabilizerness, are computationally indistinguishable from those with high nonstabilizerness. Previously, such computational indistinguishability has been studied with respect to entanglement, introducing the concept of pseudoentanglement. However, we demonstrate that pseudomagic neither follows from pseudoentanglement nor implies it. In terms of applications, the study of pseudomagic offers fresh insights into the theory of quantum scrambling: it uncovers states that, even though they originate from non-scrambling unitaries, remain indistinguishable from scrambled states to any physical observer. Additional applications include new lower bounds on state synthesis problems, property testing protocols, and implications for quantum cryptography. Our work is driven by the observation that only quantities measurable by a computationally bounded observer – intrinsically limited by finite-time computational constraints – hold physical significance. Ultimately, our findings suggest that nonstabilizerness is a `hide-able' characteristic of quantum states: some states are much more magical than is apparent to a computationally bounded observer.
4.
Minki Hhan, Tomoyuki Morimae, Takashi Yamakawa
A Note on Output Length of One-Way State Generators and EFIs Poster
2024.
Tags: Poster session Monday
@Poster{P24_44,
title = {A Note on Output Length of One-Way State Generators and EFIs},
author = {Minki Hhan and Tomoyuki Morimae and Takashi Yamakawa},
year = {2024},
date = {2024-01-01},
keywords = {Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
5.
Ragesh Jaiswal
A Quantum Approximation Scheme for k-Means Poster
2024.
Abstract | Tags: Poster session Monday | Links:
@Poster{P24_5,
title = {A Quantum Approximation Scheme for k-Means},
author = {Ragesh Jaiswal},
url = {https://arxiv.org/abs/2308.08167},
year = {2024},
date = {2024-01-01},
abstract = {We give a quantum approximation scheme (i.e., (1+ε)-approximation for every ε>0) for the classical k-means clustering problem in the QRAM model with a running time that has only polylogarithmic dependence on the number of data points. This is the first quantum algorithm with a polylogarithmic running time that gives a provable approximation guarantee of (1+ε) for the k-means problem. Also, unlike previous works on unsupervised learning, our quantum algorithm does not require quantum linear algebra subroutines and has a running time independent of parameters (e.g., condition number) that appear in such procedures.},
keywords = {Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
We give a quantum approximation scheme (i.e., (1+ε)-approximation for every ε>0) for the classical k-means clustering problem in the QRAM model with a running time that has only polylogarithmic dependence on the number of data points. This is the first quantum algorithm with a polylogarithmic running time that gives a provable approximation guarantee of (1+ε) for the k-means problem. Also, unlike previous works on unsupervised learning, our quantum algorithm does not require quantum linear algebra subroutines and has a running time independent of parameters (e.g., condition number) that appear in such procedures.
6.
Guillermo Currás-Lorenzo, Margarida Pereira, Go Kato, Marcos Curty, Kiyoshi Tamaki
A security framework for quantum key distribution implementations Poster
2024.
Tags: Poster session Monday
@Poster{P24_212,
title = {A security framework for quantum key distribution implementations},
author = {Guillermo Currás-Lorenzo and Margarida Pereira and Go Kato and Marcos Curty and Kiyoshi Tamaki},
year = {2024},
date = {2024-01-01},
keywords = {Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
7.
Xian Wang, Mahmut Sait Okyay, Bryan M. Wong
Accelerating quantum optimal control of multi-qubit systems with symmetry-based Hamiltonian transformations Poster
2024.
Abstract | Tags: Poster session Monday | Links:
@Poster{P24_9,
title = {Accelerating quantum optimal control of multi-qubit systems with symmetry-based Hamiltonian transformations},
author = {Xian Wang and Mahmut Sait Okyay and Bryan M. Wong},
url = {https://doi.org/10.1116/5.0162455},
year = {2024},
date = {2024-01-01},
abstract = {We present a novel, computationally efficient approach to accelerate quantum optimal control calculations of large multi-qubit systems. By leveraging the system's intrinsic symmetry, the Hilbert space can be decomposed and the Hamiltonians block diagonalized to enable extremely fast quantum optimal control calculations. Our approach reduces the computational runtime of qubit optimal control calculations by orders of magnitude while maintaining the same accuracy as the original method. This symmetry-based method can be generalized to a variety of multi-qubit systems with Trotterization techniques. As prospective applications, we propose the concept of symmetry-protected subspaces, which can be potential platforms for preparing symmetric states, realizing quantum gates simultaneously, quantum error suppression, and quantum simulation.},
keywords = {Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
We present a novel, computationally efficient approach to accelerate quantum optimal control calculations of large multi-qubit systems. By leveraging the system's intrinsic symmetry, the Hilbert space can be decomposed and the Hamiltonians block diagonalized to enable extremely fast quantum optimal control calculations. Our approach reduces the computational runtime of qubit optimal control calculations by orders of magnitude while maintaining the same accuracy as the original method. This symmetry-based method can be generalized to a variety of multi-qubit systems with Trotterization techniques. As prospective applications, we propose the concept of symmetry-protected subspaces, which can be potential platforms for preparing symmetric states, realizing quantum gates simultaneously, quantum error suppression, and quantum simulation.
8.
Zain Saleem, Michael A Perlin, Anil Shaji, Stephen Gray
Achieving the Heisenberg limit with Dicke States in noisy quantum meterology Poster
2024.
Tags: Poster session Monday
@Poster{P24_80,
title = {Achieving the Heisenberg limit with Dicke States in noisy quantum meterology},
author = {Zain Saleem and Michael A Perlin and Anil Shaji and Stephen Gray},
year = {2024},
date = {2024-01-01},
keywords = {Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
9.
Hayata Yamasaki, Natsuto Isogai, Mio Murao
Advantage of Quantum Machine Learning from General Computational Advantages Poster
2024.
Tags: Poster session Monday
@Poster{P24_275,
title = {Advantage of Quantum Machine Learning from General Computational Advantages},
author = {Hayata Yamasaki and Natsuto Isogai and Mio Murao},
year = {2024},
date = {2024-01-01},
keywords = {Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
10.
Oles Shtanko, Weishun Zhong, Ramis Movassagh
Advantage of Quantum Neural Networks as Quantum Information Decoders Poster
2024.
Tags: Poster session Monday
@Poster{P24_138,
title = {Advantage of Quantum Neural Networks as Quantum Information Decoders},
author = {Oles Shtanko and Weishun Zhong and Ramis Movassagh},
year = {2024},
date = {2024-01-01},
keywords = {Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
11.
Naoto Shiraishi, Ryuji Takagi
Alchemy of quantum coherence: Arbitrary amplification in catalytic and asymptotic coherence manipulation Poster
2024.
Abstract | Tags: Poster session Monday | Links:
@Poster{P24_165,
title = {Alchemy of quantum coherence: Arbitrary amplification in catalytic and asymptotic coherence manipulation},
author = {Naoto Shiraishi and Ryuji Takagi},
url = {https://arxiv.org/abs/2308.12338},
year = {2024},
date = {2024-01-01},
abstract = {Quantum coherence is one of the fundamental aspects distinguishing classical and quantum theories. Coherence between different energy eigenstates is particularly important, as it serves as a valuable resource under the law of energy conservation. A fundamental question in this setting is how well one can prepare good coherent states from low coherent states and whether a given coherent state is convertible to another one. Here, we show that any low coherent state is convertible to any high coherent state arbitrarily well in two operational settings: asymptotic and catalytic transformations. For a variant of asymptotic coherence manipulation where one aims to prepare desired states in local subsystems, the rate of transformation becomes unbounded regardless of how weak the initial coherence is. In a non-asymptotic transformation with a catalyst, a helper state that locally remains in the original form after the transformation, we show that an arbitrary state can be obtained from any low coherent state. Applying this to the standard asymptotic setting, we find that a catalyst can increase the coherence distillation rate significantly—from zero to infinite rate. We also prove that such anomalous transformation requires small but non-zero coherence in relevant modes, establishing the condition under which a sharp transition of the operational capability occurs. Our results provide a general characterization of the coherence transformability in these operational settings and showcase their peculiar properties compared to other common resource theories such as entanglement and quantum thermodynamics.},
keywords = {Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
Quantum coherence is one of the fundamental aspects distinguishing classical and quantum theories. Coherence between different energy eigenstates is particularly important, as it serves as a valuable resource under the law of energy conservation. A fundamental question in this setting is how well one can prepare good coherent states from low coherent states and whether a given coherent state is convertible to another one. Here, we show that any low coherent state is convertible to any high coherent state arbitrarily well in two operational settings: asymptotic and catalytic transformations. For a variant of asymptotic coherence manipulation where one aims to prepare desired states in local subsystems, the rate of transformation becomes unbounded regardless of how weak the initial coherence is. In a non-asymptotic transformation with a catalyst, a helper state that locally remains in the original form after the transformation, we show that an arbitrary state can be obtained from any low coherent state. Applying this to the standard asymptotic setting, we find that a catalyst can increase the coherence distillation rate significantly—from zero to infinite rate. We also prove that such anomalous transformation requires small but non-zero coherence in relevant modes, establishing the condition under which a sharp transition of the operational capability occurs. Our results provide a general characterization of the coherence transformability in these operational settings and showcase their peculiar properties compared to other common resource theories such as entanglement and quantum thermodynamics.
12.
Pierre Botteron, Anne Broadbent, Reda Chhaibi, Ion Nechita, Clément Pellegrini
Algebra of Nonlocal Boxes and the Collapse of Communication Complexity Poster
2024.
Tags: Poster session Monday
@Poster{P24_171,
title = {Algebra of Nonlocal Boxes and the Collapse of Communication Complexity},
author = {Pierre Botteron and Anne Broadbent and Reda Chhaibi and Ion Nechita and Clément Pellegrini},
year = {2024},
date = {2024-01-01},
keywords = {Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
13.
Ryan Mann, Romy Minko
Algorithmic Cluster Expansions for Quantum Problems Poster
2024.
Abstract | Tags: Poster session Monday | Links:
@Poster{P24_52,
title = {Algorithmic Cluster Expansions for Quantum Problems},
author = {Ryan Mann and Romy Minko},
url = {https://arxiv.org/abs/2306.08974 https://tqc-conference.org/wp-content/uploads/cfdb7_uploads/1716175598-poster-52.pdf},
year = {2024},
date = {2024-01-01},
abstract = {We establish a general framework for developing approximation algorithms for a class of counting problems. Our framework is based on the cluster expansion of abstract polymer models formalism of Kotecký and Preiss. We apply our framework to obtain efficient algorithms for (1) approximating probability amplitudes of a class of quantum circuits close to the identity, (2) approximating expectation values of a class of quantum circuits with operators close to the identity, (3) approximating partition functions of a class of quantum spin systems at high temperature, and (4) approximating thermal expectation values of a class of quantum spin systems at high temperature with positive-semidefinite operators. Further, we obtain hardness of approximation results for approximating probability amplitudes of quantum circuits and partition functions of quantum spin systems. This establishes a computational complexity transition for these problems and shows that our algorithmic conditions are optimal under complexity-theoretic assumptions. Finally, we show that our algorithmic condition is almost optimal for expectation values and optimal for thermal expectation values in the sense of zero freeness.},
keywords = {Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
We establish a general framework for developing approximation algorithms for a class of counting problems. Our framework is based on the cluster expansion of abstract polymer models formalism of Kotecký and Preiss. We apply our framework to obtain efficient algorithms for (1) approximating probability amplitudes of a class of quantum circuits close to the identity, (2) approximating expectation values of a class of quantum circuits with operators close to the identity, (3) approximating partition functions of a class of quantum spin systems at high temperature, and (4) approximating thermal expectation values of a class of quantum spin systems at high temperature with positive-semidefinite operators. Further, we obtain hardness of approximation results for approximating probability amplitudes of quantum circuits and partition functions of quantum spin systems. This establishes a computational complexity transition for these problems and shows that our algorithmic conditions are optimal under complexity-theoretic assumptions. Finally, we show that our algorithmic condition is almost optimal for expectation values and optimal for thermal expectation values in the sense of zero freeness.
14.
Léo Colisson, Damian Markham, Raja Yehia
All graph state verification protocols are composably secure Poster
2024.
Tags: Poster session Monday
@Poster{P24_170,
title = {All graph state verification protocols are composably secure},
author = {Léo Colisson and Damian Markham and Raja Yehia},
year = {2024},
date = {2024-01-01},
keywords = {Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
15.
Edoardo Alessandroni, Sergi Ramos-Calderer, Ingo Roth
Alleviating the quantum Big-M problem Poster
2024.
Abstract | Tags: Poster session Monday | Links:
@Poster{P24_289,
title = {Alleviating the quantum Big-M problem},
author = {Edoardo Alessandroni and Sergi Ramos-Calderer and Ingo Roth},
url = {https://arxiv.org/abs/2307.10379},
year = {2024},
date = {2024-01-01},
abstract = {A major obstacle for quantum optimizers is the reformulation of constraints as a quadratic unconstrained binary optimization (QUBO). Current QUBO translators exaggerate the weight M of the penalty terms. Classically known as the "Big-M" problem, the issue becomes even more daunting for quantum solvers, since it affects the physical energy scale. We take a systematic, encompassing look at the quantum big-M problem, revealing NP-hardness in finding the optimal M and establishing bounds on the Hamiltonian spectral gap Δ, inversely related to the expected run-time of quantum solvers. We propose a practical translation algorithm, based on SDP relaxation, that outperforms previous methods in numerical benchmarks. Our algorithm gives values of Δ orders of magnitude greater, e.g. for portfolio optimization instances. Solving such instances with an adiabatic algorithm on 6-qubits of an IonQ device, we observe significant advantages in time to solution and average solution quality. Our findings are relevant to quantum and quantum-inspired solvers alike.},
keywords = {Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
A major obstacle for quantum optimizers is the reformulation of constraints as a quadratic unconstrained binary optimization (QUBO). Current QUBO translators exaggerate the weight M of the penalty terms. Classically known as the "Big-M" problem, the issue becomes even more daunting for quantum solvers, since it affects the physical energy scale. We take a systematic, encompassing look at the quantum big-M problem, revealing NP-hardness in finding the optimal M and establishing bounds on the Hamiltonian spectral gap Δ, inversely related to the expected run-time of quantum solvers. We propose a practical translation algorithm, based on SDP relaxation, that outperforms previous methods in numerical benchmarks. Our algorithm gives values of Δ orders of magnitude greater, e.g. for portfolio optimization instances. Solving such instances with an adiabatic algorithm on 6-qubits of an IonQ device, we observe significant advantages in time to solution and average solution quality. Our findings are relevant to quantum and quantum-inspired solvers alike.
16.
Sascha Heußen
Applications of topological fault-tolerant quantum error correction in near-term devices Poster
2024.
Tags: Poster session Monday
@Poster{P24_29,
title = {Applications of topological fault-tolerant quantum error correction in near-term devices},
author = {Sascha Heußen},
year = {2024},
date = {2024-01-01},
keywords = {Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
17.
Zackary Jorquera, Steven Kordonowy, Stuart Wayland, Alexandra Kolla, Charlie Carlson
Approximation Algorithms for Quantum Max-d-Cut Poster
2024.
Tags: Poster session Monday
@Poster{P24_210,
title = {Approximation Algorithms for Quantum Max-d-Cut},
author = {Zackary Jorquera and Steven Kordonowy and Stuart Wayland and Alexandra Kolla and Charlie Carlson},
year = {2024},
date = {2024-01-01},
keywords = {Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
18.
Bivas Mallick, Saheli Mukherjee, Ananda Gopal Maity, Archan S. Majumdar
Assessing non-Markovian dynamics through moments of the Choi state Poster
2024.
Tags: Poster session Monday
@Poster{P24_179,
title = {Assessing non-Markovian dynamics through moments of the Choi state},
author = {Bivas Mallick and Saheli Mukherjee and Ananda Gopal Maity and Archan S. Majumdar},
year = {2024},
date = {2024-01-01},
keywords = {Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
19.
Nadish Silva, Ming Yin, Sergii Strelchuk
Bases for optimising stabiliser decompositions of quantum states Poster
2024.
Tags: Poster session Monday
@Poster{P24_231,
title = {Bases for optimising stabiliser decompositions of quantum states},
author = {Nadish Silva and Ming Yin and Sergii Strelchuk},
year = {2024},
date = {2024-01-01},
keywords = {Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
20.
Michele Dall'Arno
Bayesian inference of quantum devices Poster
2024.
Abstract | Tags: Poster session Monday | Links:
@Poster{P24_90,
title = {Bayesian inference of quantum devices},
author = {Michele Dall'Arno},
url = {https://arxiv.org/abs/2304.13258},
year = {2024},
date = {2024-01-01},
abstract = {We consider the scenario in which a black box with buttons and light bulbs is given so that, if any button is pressed a certain number of times, the corresponding probability distribution on the light bulbs lighting up can be observed. We model the black box as a prepare-and-measure setup, that is, an unspecified state is prepared upon the pressure of any button, and an unspecified measurement is performed on such a state.
We consider the problem of the Bayesian inference of, say, the measurement (but, of course, we could consider the dual problem of inferring the states), that is, we aim at finding the measurement that maximizes the Bayesian posterior probability density, given the observations, for any given prior probability density on states and measurements.
Our main result is to characterize such optimal measurements in the informationally complete (IC) case when uniform probability densities (i.e. maximal ignorance) are assumed on states and measurements. In particular, we prove that any measurement that produces the observations upon the input of a 2-design set of states is optimal, thus settling in closed-form the case of non-overcomplete measurements, for which the only 2-design is the symmetric, informationally complete (SIC) set of states. Being data-driven, the inferential setup we consider offers a solution to the chicken-or-egg problem of usual quantum tomography, that is, the fact that the tomography of a measurement requires the knowledge of the input states, whereas the tomography of the states requires the knowledge of the measurement, in a neverending loop.},
keywords = {Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
We consider the scenario in which a black box with buttons and light bulbs is given so that, if any button is pressed a certain number of times, the corresponding probability distribution on the light bulbs lighting up can be observed. We model the black box as a prepare-and-measure setup, that is, an unspecified state is prepared upon the pressure of any button, and an unspecified measurement is performed on such a state.
We consider the problem of the Bayesian inference of, say, the measurement (but, of course, we could consider the dual problem of inferring the states), that is, we aim at finding the measurement that maximizes the Bayesian posterior probability density, given the observations, for any given prior probability density on states and measurements.
Our main result is to characterize such optimal measurements in the informationally complete (IC) case when uniform probability densities (i.e. maximal ignorance) are assumed on states and measurements. In particular, we prove that any measurement that produces the observations upon the input of a 2-design set of states is optimal, thus settling in closed-form the case of non-overcomplete measurements, for which the only 2-design is the symmetric, informationally complete (SIC) set of states. Being data-driven, the inferential setup we consider offers a solution to the chicken-or-egg problem of usual quantum tomography, that is, the fact that the tomography of a measurement requires the knowledge of the input states, whereas the tomography of the states requires the knowledge of the measurement, in a neverending loop.
We consider the problem of the Bayesian inference of, say, the measurement (but, of course, we could consider the dual problem of inferring the states), that is, we aim at finding the measurement that maximizes the Bayesian posterior probability density, given the observations, for any given prior probability density on states and measurements.
Our main result is to characterize such optimal measurements in the informationally complete (IC) case when uniform probability densities (i.e. maximal ignorance) are assumed on states and measurements. In particular, we prove that any measurement that produces the observations upon the input of a 2-design set of states is optimal, thus settling in closed-form the case of non-overcomplete measurements, for which the only 2-design is the symmetric, informationally complete (SIC) set of states. Being data-driven, the inferential setup we consider offers a solution to the chicken-or-egg problem of usual quantum tomography, that is, the fact that the tomography of a measurement requires the knowledge of the input states, whereas the tomography of the states requires the knowledge of the measurement, in a neverending loop.
21.
Jonas Kamminga, Sevag Gharibian
BQP, meet NP: Search-to-decision reductions and approximate counting Poster
2024.
Abstract | Tags: Poster session Monday | Links:
@Poster{P24_35,
title = {BQP, meet NP: Search-to-decision reductions and approximate counting},
author = {Jonas Kamminga and Sevag Gharibian},
url = {https://arxiv.org/abs/2401.03943},
year = {2024},
date = {2024-01-01},
abstract = {What is the power of polynomial-time quantum computation with access to an NP oracle? In this work, we focus on two fundamental tasks from the study of Boolean satisfiability (SAT) problems: search-to-decision reductions, and approximate counting. We first show that, in strong contrast to the classical setting where a poly-time Turing machine requires Θ(n) queries to an NP oracle to compute a witness to a given SAT formula, quantumly Θ(logn) queries suffice. We then show this is tight in the black-box model - any quantum algorithm with "NP-like" query access to a formula requires Ω(logn) queries to extract a solution with constant probability. Moving to approximate counting of SAT solutions, by exploiting a quantum link between search-to-decision reductions and approximate counting, we show that existing classical approximate counting algorithms are likely optimal. First, we give a lower bound in the "NP-like" black-box query setting: Approximate counting requires Ω(logn) queries, even on a quantum computer. We then give a "white-box" lower bound (i.e. where the input formula is not hidden in the oracle) - if there exists a randomized poly-time classical or quantum algorithm for approximate counting making o(logn) NP queries, then BPP^NP[o(n)] contains a P^NP-complete problem if the algorithm is classical and FBQP^NP[o(n)] contains an FP^NP-complete problem if the algorithm is quantum.},
keywords = {Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
What is the power of polynomial-time quantum computation with access to an NP oracle? In this work, we focus on two fundamental tasks from the study of Boolean satisfiability (SAT) problems: search-to-decision reductions, and approximate counting. We first show that, in strong contrast to the classical setting where a poly-time Turing machine requires Θ(n) queries to an NP oracle to compute a witness to a given SAT formula, quantumly Θ(logn) queries suffice. We then show this is tight in the black-box model - any quantum algorithm with "NP-like" query access to a formula requires Ω(logn) queries to extract a solution with constant probability. Moving to approximate counting of SAT solutions, by exploiting a quantum link between search-to-decision reductions and approximate counting, we show that existing classical approximate counting algorithms are likely optimal. First, we give a lower bound in the "NP-like" black-box query setting: Approximate counting requires Ω(logn) queries, even on a quantum computer. We then give a "white-box" lower bound (i.e. where the input formula is not hidden in the oracle) - if there exists a randomized poly-time classical or quantum algorithm for approximate counting making o(logn) NP queries, then BPP^NP[o(n)] contains a P^NP-complete problem if the algorithm is classical and FBQP^NP[o(n)] contains an FP^NP-complete problem if the algorithm is quantum.
22.
Chung-Yun Hsieh, Huan-Yu Ku, Shin-Liang Chen, Yueh-Nan Chen, Costantino Budroni
Can we stochastically distil quantum steering and measurement incompatibility? Poster
2024.
Tags: Poster session Monday
@Poster{P24_37,
title = {Can we stochastically distil quantum steering and measurement incompatibility?},
author = {Chung-Yun Hsieh and Huan-Yu Ku and Shin-Liang Chen and Yueh-Nan Chen and Costantino Budroni},
year = {2024},
date = {2024-01-01},
keywords = {Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
23.
Minjeong Song, Varun Narasimhachar, Bartosz Regula, Thomas Elliott, Mile Gu
Causal Classification of Spatiotemporal Quantum Correlations Poster
2024.
Tags: Poster session Monday
@Poster{P24_164,
title = {Causal Classification of Spatiotemporal Quantum Correlations},
author = {Minjeong Song and Varun Narasimhachar and Bartosz Regula and Thomas Elliott and Mile Gu},
year = {2024},
date = {2024-01-01},
keywords = {Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
24.
Kathleen Barsse, Paolo Perinotti, Alessandro Tosini, Leonardo Vaglini
Causal influence versus signalling for interacting quantum channels Poster
2024.
Tags: Poster session Monday
@Poster{P24_88,
title = {Causal influence versus signalling for interacting quantum channels},
author = {Kathleen Barsse and Paolo Perinotti and Alessandro Tosini and Leonardo Vaglini},
year = {2024},
date = {2024-01-01},
keywords = {Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
25.
Changhao Yi, Xiaodi Li, Huangjun Zhu
Certifying entanglement dimensionality by the moment method Poster
2024.
Abstract | Tags: Poster session Monday
@Poster{P24_95,
title = {Certifying entanglement dimensionality by the moment method},
author = {Changhao Yi and Xiaodi Li and Huangjun Zhu},
year = {2024},
date = {2024-01-01},
abstract = {In this paper, we combine the k-reduction map, the moment method and the classical shadow
method into a practical entanglement dimensionality certification protocol. The core of our protocol
utilizes finite order reduction moments of the target state to determine if it remains positive under
the application of the k-reduction map. First, we study the spectrum of the k-reduced operators.
Further, similar with the entanglement negativity, we introduce the definition of k-reduction neg-
ativity, explore its properties to characterize the violation of the criterion. Second, we apply the
moment methods to the k-reduction map, and construct the reduction moment criteria systemati-
cally by considering the spectrum information. Our final protocol applies to a much wider range of
states than the fidelity-based methods. Additionally, our method only requires a unitary-3 design,
making it more feasible in practice than the correlation matrix method. We further explore the de-
tectable abilities of different protocols and demonstrate the efficiency of our protocol with analytical and numerical examples},
keywords = {Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
In this paper, we combine the k-reduction map, the moment method and the classical shadow
method into a practical entanglement dimensionality certification protocol. The core of our protocol
utilizes finite order reduction moments of the target state to determine if it remains positive under
the application of the k-reduction map. First, we study the spectrum of the k-reduced operators.
Further, similar with the entanglement negativity, we introduce the definition of k-reduction neg-
ativity, explore its properties to characterize the violation of the criterion. Second, we apply the
moment methods to the k-reduction map, and construct the reduction moment criteria systemati-
cally by considering the spectrum information. Our final protocol applies to a much wider range of
states than the fidelity-based methods. Additionally, our method only requires a unitary-3 design,
making it more feasible in practice than the correlation matrix method. We further explore the de-
tectable abilities of different protocols and demonstrate the efficiency of our protocol with analytical and numerical examples
method into a practical entanglement dimensionality certification protocol. The core of our protocol
utilizes finite order reduction moments of the target state to determine if it remains positive under
the application of the k-reduction map. First, we study the spectrum of the k-reduced operators.
Further, similar with the entanglement negativity, we introduce the definition of k-reduction neg-
ativity, explore its properties to characterize the violation of the criterion. Second, we apply the
moment methods to the k-reduction map, and construct the reduction moment criteria systemati-
cally by considering the spectrum information. Our final protocol applies to a much wider range of
states than the fidelity-based methods. Additionally, our method only requires a unitary-3 design,
making it more feasible in practice than the correlation matrix method. We further explore the de-
tectable abilities of different protocols and demonstrate the efficiency of our protocol with analytical and numerical examples
26.
Edwin Peter Lobo, Jef Pauwels, Stefano Pironio
Certifying long-range quantum correlations in routed Bell tests Poster
2024.
Tags: Poster session Monday
@Poster{P24_97,
title = {Certifying long-range quantum correlations in routed Bell tests},
author = {Edwin Peter Lobo and Jef Pauwels and Stefano Pironio},
year = {2024},
date = {2024-01-01},
keywords = {Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
27.
Elia Zanoni, Carlo Maria Scandolo
Choi-Defined Resource Theories Poster
2024.
Tags: Poster session Monday
@Poster{P24_200,
title = {Choi-Defined Resource Theories},
author = {Elia Zanoni and Carlo Maria Scandolo},
year = {2024},
date = {2024-01-01},
keywords = {Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
28.
Xiao-Ming Zhang, Xiao Yuan
Circuit complexity of quantum access models for encoding classical data Poster
2024.
Tags: Poster session Monday
@Poster{P24_53,
title = {Circuit complexity of quantum access models for encoding classical data},
author = {Xiao-Ming Zhang and Xiao Yuan},
year = {2024},
date = {2024-01-01},
keywords = {Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
29.
Changhun Oh, Minzhao Liu, Yuri Alexeev, Bill Fefferman, Liang Jiang
Classical algorithm for simulating experimental Gaussian boson sampling Poster
2024.
Tags: Poster session Monday
@Poster{P24_144,
title = {Classical algorithm for simulating experimental Gaussian boson sampling},
author = {Changhun Oh and Minzhao Liu and Yuri Alexeev and Bill Fefferman and Liang Jiang},
year = {2024},
date = {2024-01-01},
keywords = {Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
30.
Yosuke Mitsuhashi, Nobuyuki Yoshioka
Clifford Group and Unitary Designs under Symmetry Poster
2024.
Tags: Poster session Monday
@Poster{P24_153,
title = {Clifford Group and Unitary Designs under Symmetry},
author = {Yosuke Mitsuhashi and Nobuyuki Yoshioka},
year = {2024},
date = {2024-01-01},
keywords = {Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
31.
Yusuke Kimura, Tomotaka Kuwahara
Clustering theorem in 1D long-range interacting systems at arbitrary temperatures Poster
2024.
Abstract | Tags: Outstanding Poster, Poster session Monday | Links:
@Poster{P24_135,
title = {Clustering theorem in 1D long-range interacting systems at arbitrary temperatures},
author = {Yusuke Kimura and Tomotaka Kuwahara},
url = {https://arxiv.org/abs/2403.11431},
year = {2024},
date = {2024-01-01},
abstract = {This paper delves into a fundamental aspect of quantum statistical mechanics – the absence of thermal phase transitions in one-dimensional (1D) systems. Originating from Ising's analysis of the 1D spin chain, this concept has been pivotal in understanding 1D quantum phases, especially those with finite-range interactions as extended by Araki. In this work, we focus on quantum long-range interactions and successfully derive a clustering theorem applicable to a wide range of interaction decays at arbitrary temperatures. This theorem applies to any interaction forms that decay faster than r^-2 and does not rely on translation invariance or infinite system size assumptions. Also, we rigorously established that the temperature dependence of the correlation length is given by e^const.β, which is the same as the classical cases. Our findings indicate the absence of phase transitions in 1D systems with super-polynomially decaying interactions, thereby expanding upon previous theoretical research. To overcome significant technical challenges originating from the divergence of the imaginary-time Lieb-Robinson bound, we utilize the quantum belief propagation to refine the cluster expansion method. This approach allowed us to address divergence issues effectively and contributed to a deeper understanding of low-temperature behaviors in 1D quantum systems.},
keywords = {Outstanding Poster, Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
This paper delves into a fundamental aspect of quantum statistical mechanics – the absence of thermal phase transitions in one-dimensional (1D) systems. Originating from Ising's analysis of the 1D spin chain, this concept has been pivotal in understanding 1D quantum phases, especially those with finite-range interactions as extended by Araki. In this work, we focus on quantum long-range interactions and successfully derive a clustering theorem applicable to a wide range of interaction decays at arbitrary temperatures. This theorem applies to any interaction forms that decay faster than r^-2 and does not rely on translation invariance or infinite system size assumptions. Also, we rigorously established that the temperature dependence of the correlation length is given by e^const.β, which is the same as the classical cases. Our findings indicate the absence of phase transitions in 1D systems with super-polynomially decaying interactions, thereby expanding upon previous theoretical research. To overcome significant technical challenges originating from the divergence of the imaginary-time Lieb-Robinson bound, we utilize the quantum belief propagation to refine the cluster expansion method. This approach allowed us to address divergence issues effectively and contributed to a deeper understanding of low-temperature behaviors in 1D quantum systems.
32.
Alisa Haukisalmi, Matti Raasakka, Ilkka Tittonen
Comparing resource requirements of noisy quantum simulation algorithms for the Tavis-Cummings model Poster
2024.
Abstract | Tags: Poster session Monday | Links:
@Poster{P24_25,
title = {Comparing resource requirements of noisy quantum simulation algorithms for the Tavis-Cummings model},
author = {Alisa Haukisalmi and Matti Raasakka and Ilkka Tittonen},
url = {https://arxiv.org/abs/2402.16692},
year = {2024},
date = {2024-01-01},
abstract = {Fault-tolerant quantum computers could facilitate the simulation of quantum systems unfeasible for classical computation. However, the noisy intermediate-scale quantum (NISQ) devices of the present and near-term are limited, and their utilization requires additional strategies. These include quantum error mitigation (QEM) for alleviating device noise and variational quantum algorithms (VQAs), which combine classical optimization with short-depth parameterized quantum circuits. We compare two such methods: zero-noise extrapolation (ZNE) with noise amplification by circuit folding, and incremental structural learning (ISL), a type of circuit recompiling VQA. These are applied to trotterized time-evolution of the Tavis-Cummings model (TCM) under a noise simulation. Since both methods add circuit evaluation overhead, it is of interest to see how they compare both in the accuracy of the dynamics they produce, and in terms of the quantum resources used. Additionally, noisy recompilation of time-evolution circuits with ISL has not previously been explored to our knowledge. We find that while ISL achieves lower error than ZNE for smaller system sizes, it fails to produce correct dynamics for 4 qubits, where ZNE is superior. Diverging resource requirements for ISL and ZNE are observed, with ISL achieving low circuit depths at the cost of a large number of circuit evaluations.},
keywords = {Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
Fault-tolerant quantum computers could facilitate the simulation of quantum systems unfeasible for classical computation. However, the noisy intermediate-scale quantum (NISQ) devices of the present and near-term are limited, and their utilization requires additional strategies. These include quantum error mitigation (QEM) for alleviating device noise and variational quantum algorithms (VQAs), which combine classical optimization with short-depth parameterized quantum circuits. We compare two such methods: zero-noise extrapolation (ZNE) with noise amplification by circuit folding, and incremental structural learning (ISL), a type of circuit recompiling VQA. These are applied to trotterized time-evolution of the Tavis-Cummings model (TCM) under a noise simulation. Since both methods add circuit evaluation overhead, it is of interest to see how they compare both in the accuracy of the dynamics they produce, and in terms of the quantum resources used. Additionally, noisy recompilation of time-evolution circuits with ISL has not previously been explored to our knowledge. We find that while ISL achieves lower error than ZNE for smaller system sizes, it fails to produce correct dynamics for 4 qubits, where ZNE is superior. Diverging resource requirements for ISL and ZNE are observed, with ISL achieving low circuit depths at the cost of a large number of circuit evaluations.
33.
Maarten Stroeks, Barbara Terhal
Complexity of Fermionic 2-SAT Poster
2024.
Tags: Poster session Monday
@Poster{P24_217,
title = {Complexity of Fermionic 2-SAT},
author = {Maarten Stroeks and Barbara Terhal},
year = {2024},
date = {2024-01-01},
keywords = {Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
34.
Michael Gide Jabbour, Leonardo Novo
Complexity of Gaussian Quantum Optics with a Limited Number of Non-Linearities Poster
2024.
Tags: Poster session Monday
@Poster{P24_198,
title = {Complexity of Gaussian Quantum Optics with a Limited Number of Non-Linearities},
author = {Michael Gide Jabbour and Leonardo Novo},
year = {2024},
date = {2024-01-01},
keywords = {Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
35.
Paolo Braccia, Pablo Bermejo, Lukasz Cincio, Marco Cerezo
Computing exact moments of local random quantum circuits via tensor networks Poster
2024.
Abstract | Tags: Poster session Monday | Links:
@Poster{P24_220,
title = {Computing exact moments of local random quantum circuits via tensor networks},
author = {Paolo Braccia and Pablo Bermejo and Lukasz Cincio and Marco Cerezo},
url = {https://arxiv.org/abs/2403.01706},
year = {2024},
date = {2024-01-01},
abstract = {A fundamental concept in quantum information is the computation of the moments of the distribution of expectation values. These moments describe the distribution obtained by sending a quantum state through a random unitary transformation (a circuit), sampled from some distribution, and then measuring a specific observable. While calculating these moments exactly is typically challenging, if the unitary transformation consists of local random gates, one can estimate these moments using Monte Carlo simulations of a process similar to a Markov chain. However, this method may require an impractically large number of samples or may suffer from the sign problem. In this work, we propose an alternative approach to estimate the moments using tensor networks. In this method, the operators corresponding to the moments of the local gates are represented as small dimensional tensors acting on their local commutant bases. By utilizing representation theoretical tools, we analyze the local tensor dimensions and provide bounds for the bond dimension of the matrix product states that arise from deep circuits. We compare our techniques against Monte Carlo simulations and demonstrate that our approach significantly outperforms them. Additionally, we illustrate how tensor networks can precisely compute the second moment when the unitary transformation is a quantum neural network acting on thousands of qubits and containing thousands of gates. Finally, we numerically study the anticoncentration phenomena in circuits with orthogonal random gates, a task that cannot be effectively studied using Monte Carlo methods due to sign problems.},
keywords = {Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
A fundamental concept in quantum information is the computation of the moments of the distribution of expectation values. These moments describe the distribution obtained by sending a quantum state through a random unitary transformation (a circuit), sampled from some distribution, and then measuring a specific observable. While calculating these moments exactly is typically challenging, if the unitary transformation consists of local random gates, one can estimate these moments using Monte Carlo simulations of a process similar to a Markov chain. However, this method may require an impractically large number of samples or may suffer from the sign problem. In this work, we propose an alternative approach to estimate the moments using tensor networks. In this method, the operators corresponding to the moments of the local gates are represented as small dimensional tensors acting on their local commutant bases. By utilizing representation theoretical tools, we analyze the local tensor dimensions and provide bounds for the bond dimension of the matrix product states that arise from deep circuits. We compare our techniques against Monte Carlo simulations and demonstrate that our approach significantly outperforms them. Additionally, we illustrate how tensor networks can precisely compute the second moment when the unitary transformation is a quantum neural network acting on thousands of qubits and containing thousands of gates. Finally, we numerically study the anticoncentration phenomena in circuits with orthogonal random gates, a task that cannot be effectively studied using Monte Carlo methods due to sign problems.
36.
Ivan Derkach, Adnan A. E. Hajomer, Radim Filip, Ulrik L. Andersen, Vladyslav C. Usenko, Tobias Gehring
Continuous-variable quantum passive optical networks Poster
2024.
Tags: Poster session Monday
@Poster{P24_213,
title = {Continuous-variable quantum passive optical networks},
author = {Ivan Derkach and Adnan A. E. Hajomer and Radim Filip and Ulrik L. Andersen and Vladyslav C. Usenko and Tobias Gehring},
year = {2024},
date = {2024-01-01},
keywords = {Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
37.
Rene Allerstorfer, Llorenç Escolà-Farràs, Arpan Akash Ray, Boris Škorić, Florian Speelman
Continuous-variable Quantum Position Verification secure against entangled attackers Poster
2024.
Tags: Poster session Monday
@Poster{P24_178,
title = {Continuous-variable Quantum Position Verification secure against entangled attackers},
author = {Rene Allerstorfer and Llorenç Escolà-Farràs and Arpan Akash Ray and Boris Škorić and Florian Speelman},
year = {2024},
date = {2024-01-01},
keywords = {Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
38.
Kento Tsubouchi, Yosuke Mitsuhashi, Nobuyuki Yoshioka
Cost-optimal quantum error mitigation for early fault-tolerant quantum computation using white-noise approximation and symmetric Clifford twirling Poster
2024.
Tags: Poster session Monday
@Poster{P24_272,
title = {Cost-optimal quantum error mitigation for early fault-tolerant quantum computation using white-noise approximation and symmetric Clifford twirling},
author = {Kento Tsubouchi and Yosuke Mitsuhashi and Nobuyuki Yoshioka},
year = {2024},
date = {2024-01-01},
keywords = {Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
39.
Cameron Foreman, Richie Yeung, Alec Edgington, Florian Curchod
Cryptomite: A versatile and user-friendly library of randomness extractors Poster
2024.
Tags: Poster session Monday
@Poster{P24_48,
title = {Cryptomite: A versatile and user-friendly library of randomness extractors},
author = {Cameron Foreman and Richie Yeung and Alec Edgington and Florian Curchod},
year = {2024},
date = {2024-01-01},
keywords = {Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
40.
Lukas Schmitt, Christophe Piveteau, David Sutter
Cutting circuits with multiple two-qubit unitaries Poster
2024.
Tags: Poster session Monday
@Poster{P24_6,
title = {Cutting circuits with multiple two-qubit unitaries},
author = {Lukas Schmitt and Christophe Piveteau and David Sutter},
year = {2024},
date = {2024-01-01},
keywords = {Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
41.
Vikash Mittal, Jaskaran Singh, Soumyakanti Bose
Deterministic generation of hybrid entangled states using quantum walks Poster
2024.
Tags: Poster session Monday
@Poster{P24_100,
title = {Deterministic generation of hybrid entangled states using quantum walks},
author = {Vikash Mittal and Jaskaran Singh and Soumyakanti Bose},
year = {2024},
date = {2024-01-01},
keywords = {Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
42.
Nikolai Miklin, Jan Nöller, Martin Kliesch, Mariami Gachechiladze
Device-independent certification of quantum gates under the dimension assumption Poster
2024.
Tags: Poster session Monday
@Poster{P24_187,
title = {Device-independent certification of quantum gates under the dimension assumption},
author = {Nikolai Miklin and Jan Nöller and Martin Kliesch and Mariami Gachechiladze},
year = {2024},
date = {2024-01-01},
keywords = {Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
43.
Jonathan Z. Lu, Lucy Jiao, Kristina Wolinski, Milan Kornjača, Hong-Ye Hu, Sergio Cantu, Fangli Liu, Susanne F. Yelin, Sheng-Tao Wang
Digital-analog quantum learning on Rydberg atom arrays Poster
2024.
Abstract | Tags: Poster session Monday | Links:
@Poster{P24_247,
title = {Digital-analog quantum learning on Rydberg atom arrays},
author = {Jonathan Z. Lu and Lucy Jiao and Kristina Wolinski and Milan Kornjača and Hong-Ye Hu and Sergio Cantu and Fangli Liu and Susanne F. Yelin and Sheng-Tao Wang},
url = {https://arxiv.org/abs/2401.02940},
year = {2024},
date = {2024-01-01},
abstract = {We propose hybrid digital-analog learning algorithms on Rydberg atom arrays, combining the potentially practical utility and near-term realizability of quantum learning with the rapidly scaling architectures of neutral atoms. Our construction requires only single-qubit operations in the digital setting and global driving according to the Rydberg Hamiltonian in the analog setting. We perform a comprehensive numerical study of our algorithm on both classical and quantum data, given respectively by handwritten digit classification and unsupervised quantum phase boundary learning. We show in the two representative problems that digital-analog learning is not only feasible in the near term, but also requires shorter circuit depths and is more robust to realistic error models as compared to digital learning schemes. Our results suggest that digital-analog learning opens a promising path towards improved variational quantum learning experiments in the near term.},
keywords = {Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
We propose hybrid digital-analog learning algorithms on Rydberg atom arrays, combining the potentially practical utility and near-term realizability of quantum learning with the rapidly scaling architectures of neutral atoms. Our construction requires only single-qubit operations in the digital setting and global driving according to the Rydberg Hamiltonian in the analog setting. We perform a comprehensive numerical study of our algorithm on both classical and quantum data, given respectively by handwritten digit classification and unsupervised quantum phase boundary learning. We show in the two representative problems that digital-analog learning is not only feasible in the near term, but also requires shorter circuit depths and is more robust to realistic error models as compared to digital learning schemes. Our results suggest that digital-analog learning opens a promising path towards improved variational quantum learning experiments in the near term.
44.
Marco Cerezo, Martin Larocca, Diego García-Martín, Nahuel Diaz, Paolo Braccia, Enrico Fontana, Manuel Rudolph, Pablo Bermejo, Aroosa Ijaz, Supanut Thanasilp, Eric Anschuetz, Zoe Holmes
Does provable absence of barren plateaus imply classical simulability? Or, why we need to rethink variational quantum computing Poster
2024.
Tags: Poster session Monday
@Poster{P24_87,
title = {Does provable absence of barren plateaus imply classical simulability? Or, why we need to rethink variational quantum computing},
author = {Marco Cerezo and Martin Larocca and Diego García-Martín and Nahuel Diaz and Paolo Braccia and Enrico Fontana and Manuel Rudolph and Pablo Bermejo and Aroosa Ijaz and Supanut Thanasilp and Eric Anschuetz and Zoe Holmes},
year = {2024},
date = {2024-01-01},
keywords = {Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
45.
Pei Yuan, Jonathan Allcock, Shengyu Zhang
Does qubit connectivity impact quantum circuit complexity? Poster
2024.
Tags: Poster session Monday
@Poster{P24_64,
title = {Does qubit connectivity impact quantum circuit complexity?},
author = {Pei Yuan and Jonathan Allcock and Shengyu Zhang},
year = {2024},
date = {2024-01-01},
keywords = {Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
46.
Dominic Berry, Danial Motlagh, Giacomo Pantaleoni, Nathan Wiebe
Doubling efficiency of Hamiltonian simulation via Generalized Quantum Signal Processing Poster
2024.
Tags: Poster session Monday
@Poster{P24_92,
title = {Doubling efficiency of Hamiltonian simulation via Generalized Quantum Signal Processing},
author = {Dominic Berry and Danial Motlagh and Giacomo Pantaleoni and Nathan Wiebe},
year = {2024},
date = {2024-01-01},
keywords = {Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
47.
Laurin E. Fischer, Timothée Dao, Ivano Tavernelli, Francesco Tacchino
Dual frame optimization for informationally complete quantum measurements Poster
2024.
Tags: Poster session Monday
@Poster{P24_78,
title = {Dual frame optimization for informationally complete quantum measurements},
author = {Laurin E. Fischer and Timothée Dao and Ivano Tavernelli and Francesco Tacchino},
year = {2024},
date = {2024-01-01},
keywords = {Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
48.
Kun Fang, Munan Zhang, Ruqi Shi, Yinan Li
Dynamic quantum circuit compilation Poster
2024.
Tags: Poster session Monday
@Poster{P24_143,
title = {Dynamic quantum circuit compilation},
author = {Kun Fang and Munan Zhang and Ruqi Shi and Yinan Li},
year = {2024},
date = {2024-01-01},
keywords = {Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
49.
Nai-Hui Chia, Ching-Yi Lai, Han-Hsuan Lin
Efficient learning of $t$-doped stabilizer states with single-copy measurements Poster
2024.
Tags: Poster session Monday
@Poster{P24_250,
title = {Efficient learning of $t$-doped stabilizer states with single-copy measurements},
author = {Nai-Hui Chia and Ching-Yi Lai and Han-Hsuan Lin},
year = {2024},
date = {2024-01-01},
keywords = {Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
50.
Štěpán Šmíd, Roberto Bondesan
Efficient Learning of Long-Range and Equivariant Quantum Systems Poster
2024.
Abstract | Tags: Poster session Monday | Links:
@Poster{P24_28,
title = {Efficient Learning of Long-Range and Equivariant Quantum Systems},
author = {Štěpán Šmíd and Roberto Bondesan},
url = {https://arxiv.org/abs/2312.17019},
year = {2024},
date = {2024-01-01},
abstract = {In this work, we consider a fundamental task in quantum many-body physics – finding and learning ground states of quantum Hamiltonians and their properties.
Recent works have studied the task of predicting the ground state expectation value of sums of geometrically local observables by learning from data. For short-range gapped Hamiltonians, a sample complexity that is logarithmic in the number of qubits and quasipolynomial in the error was obtained.
Here we extend these results beyond the local requirements on both Hamiltonians and observables, motivated by the relevance of long-range interactions in molecular and atomic systems. For interactions decaying as a power law with exponent greater than twice the dimension of the system, we recover the same efficient logarithmic scaling with respect to the number of qubits, but the dependence on the error worsens to exponential.
Further, we show that learning algorithms equivariant under the automorphism group of the interaction hypergraph achieve a sample complexity reduction, leading in particular to a constant number of samples for learning sums of local observables in systems with periodic boundary conditions. We demonstrate the efficient scaling in practice by learning from DMRG simulations of 1D long-range and disordered systems with up to 128 qubits. Finally, we provide an analysis of the concentration of expectation values of global observables stemming from the central limit theorem, resulting in increased prediction accuracy.},
keywords = {Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
In this work, we consider a fundamental task in quantum many-body physics – finding and learning ground states of quantum Hamiltonians and their properties.
Recent works have studied the task of predicting the ground state expectation value of sums of geometrically local observables by learning from data. For short-range gapped Hamiltonians, a sample complexity that is logarithmic in the number of qubits and quasipolynomial in the error was obtained.
Here we extend these results beyond the local requirements on both Hamiltonians and observables, motivated by the relevance of long-range interactions in molecular and atomic systems. For interactions decaying as a power law with exponent greater than twice the dimension of the system, we recover the same efficient logarithmic scaling with respect to the number of qubits, but the dependence on the error worsens to exponential.
Further, we show that learning algorithms equivariant under the automorphism group of the interaction hypergraph achieve a sample complexity reduction, leading in particular to a constant number of samples for learning sums of local observables in systems with periodic boundary conditions. We demonstrate the efficient scaling in practice by learning from DMRG simulations of 1D long-range and disordered systems with up to 128 qubits. Finally, we provide an analysis of the concentration of expectation values of global observables stemming from the central limit theorem, resulting in increased prediction accuracy.
Recent works have studied the task of predicting the ground state expectation value of sums of geometrically local observables by learning from data. For short-range gapped Hamiltonians, a sample complexity that is logarithmic in the number of qubits and quasipolynomial in the error was obtained.
Here we extend these results beyond the local requirements on both Hamiltonians and observables, motivated by the relevance of long-range interactions in molecular and atomic systems. For interactions decaying as a power law with exponent greater than twice the dimension of the system, we recover the same efficient logarithmic scaling with respect to the number of qubits, but the dependence on the error worsens to exponential.
Further, we show that learning algorithms equivariant under the automorphism group of the interaction hypergraph achieve a sample complexity reduction, leading in particular to a constant number of samples for learning sums of local observables in systems with periodic boundary conditions. We demonstrate the efficient scaling in practice by learning from DMRG simulations of 1D long-range and disordered systems with up to 128 qubits. Finally, we provide an analysis of the concentration of expectation values of global observables stemming from the central limit theorem, resulting in increased prediction accuracy.
51.
Antonio Anna Mele, Yaroslav Herasymenko
Efficient learning of quantum states prepared with few fermionic non-Gaussian gates Poster
2024.
Abstract | Tags: Poster session Monday | Links:
@Poster{P24_252,
title = {Efficient learning of quantum states prepared with few fermionic non-Gaussian gates},
author = {Antonio Anna Mele and Yaroslav Herasymenko},
url = {https://arxiv.org/abs/2402.18665},
year = {2024},
date = {2024-01-01},
abstract = {The experimental realization of increasingly complex quantum states underscores the pressing need for new methods of state learning and verification. In one such framework, quantum state tomography, the aim is to learn the full quantum state from data obtained by measurements. Without prior assumptions on the state, this task is prohibitively hard. Here, we present an efficient algorithm for learning states on n fermion modes prepared by any number of Gaussian and at most t non-Gaussian gates. By Jordan-Wigner mapping, this also includes n-qubit states prepared by nearest-neighbour matchgate circuits with at most t SWAP-gates. Our algorithm is based exclusively on single-copy measurements and produces a classical representation of a state, guaranteed to be close in trace distance to the target state. The sample and time complexity of our algorithm is poly(n,2t); thus if t=O(log(n)), it is efficient. We also show that, if t scales slightly more than logarithmically, any learning algorithm to solve the same task must be inefficient, under common cryptographic assumptions. We also provide an efficient property testing algorithm that, given access to copies of a state, determines whether such state is far or close to the set of states for which our learning algorithm works. Beyond tomography, our work sheds light on the structure of states prepared with few non-Gaussian gates and offers an improved upper bound on their circuit complexity.},
keywords = {Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
The experimental realization of increasingly complex quantum states underscores the pressing need for new methods of state learning and verification. In one such framework, quantum state tomography, the aim is to learn the full quantum state from data obtained by measurements. Without prior assumptions on the state, this task is prohibitively hard. Here, we present an efficient algorithm for learning states on n fermion modes prepared by any number of Gaussian and at most t non-Gaussian gates. By Jordan-Wigner mapping, this also includes n-qubit states prepared by nearest-neighbour matchgate circuits with at most t SWAP-gates. Our algorithm is based exclusively on single-copy measurements and produces a classical representation of a state, guaranteed to be close in trace distance to the target state. The sample and time complexity of our algorithm is poly(n,2t); thus if t=O(log(n)), it is efficient. We also show that, if t scales slightly more than logarithmically, any learning algorithm to solve the same task must be inefficient, under common cryptographic assumptions. We also provide an efficient property testing algorithm that, given access to copies of a state, determines whether such state is far or close to the set of states for which our learning algorithm works. Beyond tomography, our work sheds light on the structure of states prepared with few non-Gaussian gates and offers an improved upper bound on their circuit complexity.
52.
Tobias Haug, Soovin Lee, Myungshik Kim Kim
Efficient stabilizer entropies for quantum computers Poster
2024.
Tags: Poster session Monday
@Poster{P24_207,
title = {Efficient stabilizer entropies for quantum computers},
author = {Tobias Haug and Soovin Lee and Myungshik Kim Kim},
year = {2024},
date = {2024-01-01},
keywords = {Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
53.
Hugo Thomas, Pierre-Emmanuel Emeriau, Rawad Mezher
Encoding quantum circuits onto graphs: computation of probability amplitudes via permanents Poster
2024.
Tags: Poster session Monday
@Poster{P24_174,
title = {Encoding quantum circuits onto graphs: computation of probability amplitudes via permanents},
author = {Hugo Thomas and Pierre-Emmanuel Emeriau and Rawad Mezher},
year = {2024},
date = {2024-01-01},
keywords = {Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
54.
Paul Gondolf, Tim Möbus, Cambyse Rouzé
Energy preserving evolutions over Bosonic systems Poster
2024.
Abstract | Tags: Poster session Monday | Links:
@Poster{P24_184,
title = {Energy preserving evolutions over Bosonic systems},
author = {Paul Gondolf and Tim Möbus and Cambyse Rouzé},
url = {https://arxiv.org/abs/2307.13801},
year = {2024},
date = {2024-01-01},
abstract = {The exponential convergence to invariant subspaces of quantum Markov semigroups plays a crucial role in quantum information theory. One such example is in bosonic error correction schemes, where dissipation is used to drive states back to the code-space - an invariant subspace protected against certain types of errors. In this paper, we investigate perturbations of quantum dynamical semigroups that operate on continuous variable (CV) systems and admit an invariant subspace. First, we prove a generation theorem for quantum Markov semigroups on CV systems under the physical assumptions that (i) the generator has GKSL form with corresponding jump operators defined as polynomials of annihilation and creation operators; and (ii) the (possibly unbounded) generator increases all moments in a controlled manner. Additionally, we show that the level sets of operators with bounded first moments are admissible subspaces of the evolution, providing the foundations for a perturbative analysis. Our results also extend to time-dependent semigroups. We apply our general framework to two settings of interest in continuous variables quantum information processing. First, we provide a new scheme for deriving continuity bounds on the energy-constrained capacities of Markovian perturbations of Quantum dynamical semigroups. Second, we provide quantitative perturbation bounds for the steady state of the quantum Ornstein Uhlenbeck semigroup and the invariant subspace of the photon dissipation used in bosonic error correction.},
keywords = {Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
The exponential convergence to invariant subspaces of quantum Markov semigroups plays a crucial role in quantum information theory. One such example is in bosonic error correction schemes, where dissipation is used to drive states back to the code-space - an invariant subspace protected against certain types of errors. In this paper, we investigate perturbations of quantum dynamical semigroups that operate on continuous variable (CV) systems and admit an invariant subspace. First, we prove a generation theorem for quantum Markov semigroups on CV systems under the physical assumptions that (i) the generator has GKSL form with corresponding jump operators defined as polynomials of annihilation and creation operators; and (ii) the (possibly unbounded) generator increases all moments in a controlled manner. Additionally, we show that the level sets of operators with bounded first moments are admissible subspaces of the evolution, providing the foundations for a perturbative analysis. Our results also extend to time-dependent semigroups. We apply our general framework to two settings of interest in continuous variables quantum information processing. First, we provide a new scheme for deriving continuity bounds on the energy-constrained capacities of Markovian perturbations of Quantum dynamical semigroups. Second, we provide quantitative perturbation bounds for the steady state of the quantum Ornstein Uhlenbeck semigroup and the invariant subspace of the photon dissipation used in bosonic error correction.
55.
Antonio Sannia, Francesco Tacchino, Ivano Tavernelli, Gian Luca Giorgi, Roberta Zambrini
Engineered dissipation to mitigate barren plateaus Poster
2024.
Tags: Poster session Monday
@Poster{P24_67,
title = {Engineered dissipation to mitigate barren plateaus},
author = {Antonio Sannia and Francesco Tacchino and Ivano Tavernelli and Gian Luca Giorgi and Roberta Zambrini},
year = {2024},
date = {2024-01-01},
keywords = {Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
56.
Fei Shi, Lin Chen, Giulio Chiribella, Qi Zhao
Entanglement detection length of multipartite quantum states Poster
2024.
Tags: Poster session Monday
@Poster{P24_69,
title = {Entanglement detection length of multipartite quantum states},
author = {Fei Shi and Lin Chen and Giulio Chiribella and Qi Zhao},
year = {2024},
date = {2024-01-01},
keywords = {Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
57.
Vikesh Siddhu, Dina Abdelhadi, Tomas Jochym-O'Connor, John Smolin
Entanglement sharing across a damping-dephasing channel Poster
2024.
Tags: Outstanding Poster, Poster session Monday
@Poster{P24_242,
title = {Entanglement sharing across a damping-dephasing channel},
author = {Vikesh Siddhu and Dina Abdelhadi and Tomas Jochym-O'Connor and John Smolin},
year = {2024},
date = {2024-01-01},
keywords = {Outstanding Poster, Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
58.
Ruge Lin
Entanglement Trajectory and its Boundary Poster
2024.
Abstract | Tags: Poster session Monday | Links:
@Poster{P24_66,
title = {Entanglement Trajectory and its Boundary},
author = {Ruge Lin},
url = {https://doi.org/10.22331/q-2024-03-14-1282},
year = {2024},
date = {2024-01-01},
abstract = {In this article, we present a novel approach to investigating entanglement in the context of quantum computing. Our methodology involves analyzing reduced density matrices at different stages of a quantum algorithm's execution and representing the dominant eigenvalue and von Neumann entropy on a graph, creating an "entanglement trajectory." To establish the trajectory's boundaries, we employ random matrix theory. Through the examination of examples such as quantum adiabatic computation, the Grover algorithm, and the Shor algorithm, we demonstrate that the entanglement trajectory remains within the established boundaries, exhibiting unique characteristics for each example. Moreover, we show that these boundaries and features can be extended to trajectories defined by alternative entropy measures. The entanglement trajectory serves as an invariant property of a quantum system, maintaining consistency across varying situations and definitions of entanglement. Numerical simulations accompanying this research are available via open access.},
keywords = {Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
In this article, we present a novel approach to investigating entanglement in the context of quantum computing. Our methodology involves analyzing reduced density matrices at different stages of a quantum algorithm's execution and representing the dominant eigenvalue and von Neumann entropy on a graph, creating an "entanglement trajectory." To establish the trajectory's boundaries, we employ random matrix theory. Through the examination of examples such as quantum adiabatic computation, the Grover algorithm, and the Shor algorithm, we demonstrate that the entanglement trajectory remains within the established boundaries, exhibiting unique characteristics for each example. Moreover, we show that these boundaries and features can be extended to trajectories defined by alternative entropy measures. The entanglement trajectory serves as an invariant property of a quantum system, maintaining consistency across varying situations and definitions of entanglement. Numerical simulations accompanying this research are available via open access.
59.
Ernest Y. -Z. Tan, Ramona Wolf
Entropy bounds for device-independent quantum key distribution with local Bell test Poster
2024.
Abstract | Tags: Poster session Monday | Links:
@Poster{P24_232,
title = {Entropy bounds for device-independent quantum key distribution with local Bell test},
author = {Ernest Y. -Z. Tan and Ramona Wolf},
url = {https://arxiv.org/abs/2404.00792},
year = {2024},
date = {2024-01-01},
abstract = {One of the main challenges in device-independent quantum key distribution (DIQKD) is achieving the required Bell violation over long distances, as the channel losses result in low overall detection efficiencies. Recent works have explored the concept of certifying nonlocal correlations over extended distances through the use of a local Bell test. Here, an additional quantum device is placed in close proximity to one party, using short-distance correlations to verify nonlocal behavior at long distances. However, existing works have either not resolved the question of DIQKD security against active attackers in this setup, or used methods that do not yield tight bounds on the keyrates. In this work, we introduce a general formulation of the key rate computation task in this setup that can be combined with recently developed methods for analyzing standard DIQKD. Using this method, we show that if the short-distance devices exhibit sufficiently high detection efficiencies, positive key rates can be achieved in the long-distance branch with lower detection efficiencies as compared to standard DIQKD setups. This highlights the potential for improved performance of DIQKD over extended distances in scenarios where short-distance correlations are leveraged to validate quantum correlations.},
keywords = {Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
One of the main challenges in device-independent quantum key distribution (DIQKD) is achieving the required Bell violation over long distances, as the channel losses result in low overall detection efficiencies. Recent works have explored the concept of certifying nonlocal correlations over extended distances through the use of a local Bell test. Here, an additional quantum device is placed in close proximity to one party, using short-distance correlations to verify nonlocal behavior at long distances. However, existing works have either not resolved the question of DIQKD security against active attackers in this setup, or used methods that do not yield tight bounds on the keyrates. In this work, we introduce a general formulation of the key rate computation task in this setup that can be combined with recently developed methods for analyzing standard DIQKD. Using this method, we show that if the short-distance devices exhibit sufficiently high detection efficiencies, positive key rates can be achieved in the long-distance branch with lower detection efficiencies as compared to standard DIQKD setups. This highlights the potential for improved performance of DIQKD over extended distances in scenarios where short-distance correlations are leveraged to validate quantum correlations.
60.
Haruki Emori, Hiroyasu Tajima
Error and Disturbance as Irreversibility with Applications: Unified Definition, Wigner—Araki—Yanase Theorem and Out-of-Time-Order Correlator Poster
2024.
Tags: Poster session Monday
@Poster{P24_134,
title = {Error and Disturbance as Irreversibility with Applications: Unified Definition, Wigner—Araki—Yanase Theorem and Out-of-Time-Order Correlator},
author = {Haruki Emori and Hiroyasu Tajima},
year = {2024},
date = {2024-01-01},
keywords = {Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
61.
Bujiao Wu, Dax Enshan Koh
Error-mitigated fermionic classical shadows on noisy quantum devices Poster
2024.
Tags: Poster session Monday
@Poster{P24_136,
title = {Error-mitigated fermionic classical shadows on noisy quantum devices},
author = {Bujiao Wu and Dax Enshan Koh},
year = {2024},
date = {2024-01-01},
keywords = {Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
62.
Kohdai Kuroiwa, Ryuji Takagi, Gerardo Adesso, Hayata Yamasaki
Every quantum helps: Operational advantage of quantum resources beyond convexity Poster
2024.
Abstract | Tags: Poster session Monday | Links:
@Poster{P24_241,
title = {Every quantum helps: Operational advantage of quantum resources beyond convexity},
author = {Kohdai Kuroiwa and Ryuji Takagi and Gerardo Adesso and Hayata Yamasaki},
url = {https://arxiv.org/abs/2310.09154 https://arxiv.org/abs/2310.09321},
year = {2024},
date = {2024-01-01},
abstract = {Identifying what quantum-mechanical properties are useful to untap a superior performance in quantum technologies is a pivotal question. Quantum resource theories provide a unified framework to analyze and understand such properties, as successfully demonstrated for entanglement and coherence. While these are examples of convex resources, for which quantum advantages can always be identified, many physical resources are described by a nonconvex set of free states and their interpretation has so far remained elusive. Here we address the fundamental question of the usefulness of quantum resources without convexity assumption, by providing two operational interpretations of the generalized robustness measure in general resource theories. First, we characterize the generalized robustness in terms of a nonlinear resource witness and reveal that any state is more advantageous than a free one in some multicopy channel discrimination task. Next, we consider a scenario where a theory is characterized by multiple constraints and show that the generalized robustness coincides with the worst-case advantage in a single-copy channel discrimination setting. Based on these characterizations, we conclude that every quantum resource state shows a qualitative and quantitative advantage in discrimination problems in a general resource theory even without any specification on the structure of the free states.},
keywords = {Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
Identifying what quantum-mechanical properties are useful to untap a superior performance in quantum technologies is a pivotal question. Quantum resource theories provide a unified framework to analyze and understand such properties, as successfully demonstrated for entanglement and coherence. While these are examples of convex resources, for which quantum advantages can always be identified, many physical resources are described by a nonconvex set of free states and their interpretation has so far remained elusive. Here we address the fundamental question of the usefulness of quantum resources without convexity assumption, by providing two operational interpretations of the generalized robustness measure in general resource theories. First, we characterize the generalized robustness in terms of a nonlinear resource witness and reveal that any state is more advantageous than a free one in some multicopy channel discrimination task. Next, we consider a scenario where a theory is characterized by multiple constraints and show that the generalized robustness coincides with the worst-case advantage in a single-copy channel discrimination setting. Based on these characterizations, we conclude that every quantum resource state shows a qualitative and quantitative advantage in discrimination problems in a general resource theory even without any specification on the structure of the free states.
63.
Jacob Spainhour, Akshay Seshadri, Stephen Becker
Experiment Design for Minimax Fidelity Estimation Poster
2024.
Abstract | Tags: Poster session Monday | Links:
@Poster{P24_229,
title = {Experiment Design for Minimax Fidelity Estimation},
author = {Jacob Spainhour and Akshay Seshadri and Stephen Becker},
url = {https://amath.colorado.edu/faculty/becker/Experimental_Design_Manuscript.pdf},
year = {2024},
date = {2024-01-01},
abstract = {Technological limitations require that additional resources be spent to verify the output of a quantum device. We consider this verification through the lens of fidelity estimation, in which measurements of the quantum state directly inform how “close” a constructed state is to the intended target. This is in contrast to tomography schemes that first reconstruct the complete state, as these often require a greater number of measurements to obtain a reasonably accurate estimate. To be experimentally viable, a central goal of any approach is to accurately estimate the fidelity from as few observations, and types of observations, as possible. We present a technique that designs an experimental measurement protocol of a known target state, finding one that minimizes the width of a nearly optimal minimax confidence interval around the true value of the fidelity. Importantly, the nature of the underlying fidelity estimation scheme means that this design procedure is robust to the availability of measurements, and can be designed prior to the collection of any observations.},
keywords = {Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
Technological limitations require that additional resources be spent to verify the output of a quantum device. We consider this verification through the lens of fidelity estimation, in which measurements of the quantum state directly inform how “close” a constructed state is to the intended target. This is in contrast to tomography schemes that first reconstruct the complete state, as these often require a greater number of measurements to obtain a reasonably accurate estimate. To be experimentally viable, a central goal of any approach is to accurately estimate the fidelity from as few observations, and types of observations, as possible. We present a technique that designs an experimental measurement protocol of a known target state, finding one that minimizes the width of a nearly optimal minimax confidence interval around the true value of the fidelity. Importantly, the nature of the underlying fidelity estimation scheme means that this design procedure is robust to the availability of measurements, and can be designed prior to the collection of any observations.
64.
Dar Gilboa, Jarrod McClean
Exponential Quantum Communication Advantage in Distributed Learning Poster
2024.
Tags: Poster session Monday
@Poster{P24_268,
title = {Exponential Quantum Communication Advantage in Distributed Learning},
author = {Dar Gilboa and Jarrod McClean},
year = {2024},
date = {2024-01-01},
keywords = {Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
65.
Nadish Silva, Wilfred Salmon, Ming Yin
Fast algorithms for classical specifications of stabiliser states and Clifford gates Poster
2024.
Tags: Poster session Monday
@Poster{P24_181,
title = {Fast algorithms for classical specifications of stabiliser states and Clifford gates},
author = {Nadish Silva and Wilfred Salmon and Ming Yin},
year = {2024},
date = {2024-01-01},
keywords = {Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
66.
Christopher Pattison, Gefen Baranes, Juan Pablo Bonilla Ataides, Mikhail Lukin, Hengyun Zhou
Fast quantum interconnects via constant-rate entanglement distillation Poster
2024.
Abstract | Tags: Outstanding Poster, Poster session Monday
@Poster{P24_226,
title = {Fast quantum interconnects via constant-rate entanglement distillation},
author = {Christopher Pattison and Gefen Baranes and Juan Pablo Bonilla Ataides and Mikhail Lukin and Hengyun Zhou},
year = {2024},
date = {2024-01-01},
abstract = {Distributed quantum computing allows the modular construction of large-scale quantum computers and enables new protocols for verifiably-secure quantum computation. However, such applications place stringent demands on the fidelity and rate of remote logical entanglement generation, which are not met by existing methods for quantum interconnects. In this work, we develop constant-rate entanglement distillation methods to address this bottleneck. By using a sequence of two-way entanglement distillation protocols with increasing rate, we achieve constant-rate entanglement distillation with competitive overhead. We encode the distributed Bell pairs into error-correcting codes prior to distillation, thereby making most efficient use of the noisy, distributed entanglement while only incurring a modest increase in memory footprint. We prove that our protocol achieves a constant expected ratio of physical to logical Bell pairs, for a given input error rate, and perform extensive numerical optimization to identify concrete code sequences with low overhead. We further analyze the possible improvements afforded by our scheme in the execution of concrete distributed algorithms. We find that our scheme outperforms existing quantum interconnect schemes by an order of magnitude, paving the way towards fast, distributed quantum computing.},
keywords = {Outstanding Poster, Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
Distributed quantum computing allows the modular construction of large-scale quantum computers and enables new protocols for verifiably-secure quantum computation. However, such applications place stringent demands on the fidelity and rate of remote logical entanglement generation, which are not met by existing methods for quantum interconnects. In this work, we develop constant-rate entanglement distillation methods to address this bottleneck. By using a sequence of two-way entanglement distillation protocols with increasing rate, we achieve constant-rate entanglement distillation with competitive overhead. We encode the distributed Bell pairs into error-correcting codes prior to distillation, thereby making most efficient use of the noisy, distributed entanglement while only incurring a modest increase in memory footprint. We prove that our protocol achieves a constant expected ratio of physical to logical Bell pairs, for a given input error rate, and perform extensive numerical optimization to identify concrete code sequences with low overhead. We further analyze the possible improvements afforded by our scheme in the execution of concrete distributed algorithms. We find that our scheme outperforms existing quantum interconnect schemes by an order of magnitude, paving the way towards fast, distributed quantum computing.
67.
Yue Wang, Qi Zhao
Faster Quantum Algorithms with “Fractional”-Truncated Series Poster
2024.
Tags: Poster session Monday
@Poster{P24_156,
title = {Faster Quantum Algorithms with “Fractional”-Truncated Series},
author = {Yue Wang and Qi Zhao},
year = {2024},
date = {2024-01-01},
keywords = {Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
68.
Ravishankar Ramanathan
Finite Device-Independent Extraction of a Block Min-Entropy Source against Quantum Adversaries Poster
2024.
Tags: Poster session Monday
@Poster{P24_145,
title = {Finite Device-Independent Extraction of a Block Min-Entropy Source against Quantum Adversaries},
author = {Ravishankar Ramanathan},
year = {2024},
date = {2024-01-01},
keywords = {Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
69.
Jasminder Sidhu, Thomas Brougham, Duncan McArthur, Roberto Pousa, Daniel Oi
Finite key performance of satellite quantum key distribution under practical constraints Poster
2024.
Tags: Poster session Monday
@Poster{P24_204,
title = {Finite key performance of satellite quantum key distribution under practical constraints},
author = {Jasminder Sidhu and Thomas Brougham and Duncan McArthur and Roberto Pousa and Daniel Oi},
year = {2024},
date = {2024-01-01},
keywords = {Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
70.
Junjing Xing, Tianfeng Feng, Zhaobing Fan, Haitao Ma, Kishor Bharti, Dax Koh, Yunlong Xiao
Fundamental Limitations on Communication over a Quantum Network Poster
2024.
Tags: Poster session Monday
@Poster{P24_161,
title = {Fundamental Limitations on Communication over a Quantum Network},
author = {Junjing Xing and Tianfeng Feng and Zhaobing Fan and Haitao Ma and Kishor Bharti and Dax Koh and Yunlong Xiao},
year = {2024},
date = {2024-01-01},
keywords = {Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
71.
Paolo Abiuso, Pavel Sekatski, John Calsamiglia, Martí Perarnau-Llobet
Fundamental limits of metrology at thermal equilibrium Poster
2024.
Abstract | Tags: Poster session Monday | Links:
@Poster{P24_167,
title = {Fundamental limits of metrology at thermal equilibrium},
author = {Paolo Abiuso and Pavel Sekatski and John Calsamiglia and Martí Perarnau-Llobet},
url = {https://arxiv.org/pdf/2402.06582},
year = {2024},
date = {2024-01-01},
abstract = {We consider parameter estimation on generic systems at thermal equilibrium, assuming total or partial control on their finite-dimensional Hamiltonian.
We prove that, with no constraints on the control, no fundamental advantage is offered by quantum mechanics in terms of the maximum attainable Fisher Information, which is achieved with classical (i.e. commuting) interactions, and whose optimal scaling is Heisenberg-like, i.e. quadratic in the number of constituents of the system. A quantum advantage is recovered when assuming additional constraints on the control Hamiltonian, such as a minimum energy gap between the ground state and the first excited level. Also in such case the maximum sensitivity scales as N^2. We showcase our results on paradigmatic spin-chain models. Our findings represent a fundamental bound for measurement precision on systems at equilibrium, and provide insights to equilibration theory, many-body criticality and Hamiltonian learning.},
keywords = {Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
We consider parameter estimation on generic systems at thermal equilibrium, assuming total or partial control on their finite-dimensional Hamiltonian.
We prove that, with no constraints on the control, no fundamental advantage is offered by quantum mechanics in terms of the maximum attainable Fisher Information, which is achieved with classical (i.e. commuting) interactions, and whose optimal scaling is Heisenberg-like, i.e. quadratic in the number of constituents of the system. A quantum advantage is recovered when assuming additional constraints on the control Hamiltonian, such as a minimum energy gap between the ground state and the first excited level. Also in such case the maximum sensitivity scales as N^2. We showcase our results on paradigmatic spin-chain models. Our findings represent a fundamental bound for measurement precision on systems at equilibrium, and provide insights to equilibration theory, many-body criticality and Hamiltonian learning.
We prove that, with no constraints on the control, no fundamental advantage is offered by quantum mechanics in terms of the maximum attainable Fisher Information, which is achieved with classical (i.e. commuting) interactions, and whose optimal scaling is Heisenberg-like, i.e. quadratic in the number of constituents of the system. A quantum advantage is recovered when assuming additional constraints on the control Hamiltonian, such as a minimum energy gap between the ground state and the first excited level. Also in such case the maximum sensitivity scales as N^2. We showcase our results on paradigmatic spin-chain models. Our findings represent a fundamental bound for measurement precision on systems at equilibrium, and provide insights to equilibration theory, many-body criticality and Hamiltonian learning.
72.
Alexandru Cojocaru, Juan Garay, Fang Song
Generalized Hybrid Search with Applications to Blockchain and Hash Function Security Poster
2024.
Tags: Poster session Monday
@Poster{P24_206,
title = {Generalized Hybrid Search with Applications to Blockchain and Hash Function Security},
author = {Alexandru Cojocaru and Juan Garay and Fang Song},
year = {2024},
date = {2024-01-01},
keywords = {Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
73.
Li Gao, Mizanur Mizanur Rahaman
Generalized Stein's lemma for subalgebra entropies Poster
2024.
Tags: Poster session Monday
@Poster{P24_219,
title = {Generalized Stein's lemma for subalgebra entropies},
author = {Li Gao and Mizanur Mizanur Rahaman},
year = {2024},
date = {2024-01-01},
keywords = {Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
74.
Taehee Ko, Xiantao Li, Chunhao Wang
Ground Energy and Related Properties Estimation in Quantum Chemistry with Linear Dependence on the Number of Atoms Poster
2024.
Abstract | Tags: Poster session Monday | Links:
@Poster{P24_253,
title = {Ground Energy and Related Properties Estimation in Quantum Chemistry with Linear Dependence on the Number of Atoms},
author = {Taehee Ko and Xiantao Li and Chunhao Wang},
url = {https://arxiv.org/abs/2307.07067},
year = {2024},
date = {2024-01-01},
abstract = {Density-functional theory (DFT) has revolutionized computer simulations in chemistry and material science. A faithful implementation of the theory requires self-consistent calculations. However, this effort involves repeatedly diagonalizing the Hamiltonian, for which a classical algorithm typically requires a computational complexity that scales cubically with respect to the number of electrons. This limits DFT's applicability to large-scale problems with complex chemical environments and microstructures. This article presents a quantum algorithm that has a linear scaling with respect to the number of atoms, which is much smaller than the number of electrons. Our algorithm leverages the quantum singular value transformation (QSVT) to generate a quantum circuit to encode the density-matrix, and an estimation method for computing the output electron density. In addition, we present a randomized block coordinate fixed-point method to accelerate the self-consistent field calculations by reducing the number of components of the electron density that needs to be estimated. The proposed framework is accompanied by a rigorous error analysis that quantifies the function approximation error, the statistical fluctuation, and the iteration complexity. In particular, the analysis of our self-consistent iterations takes into account the measurement noise from the quantum circuit. These advancements offer a promising avenue for tackling large-scale DFT problems, enabling simulations of complex systems that were previously computationally infeasible.},
keywords = {Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
Density-functional theory (DFT) has revolutionized computer simulations in chemistry and material science. A faithful implementation of the theory requires self-consistent calculations. However, this effort involves repeatedly diagonalizing the Hamiltonian, for which a classical algorithm typically requires a computational complexity that scales cubically with respect to the number of electrons. This limits DFT's applicability to large-scale problems with complex chemical environments and microstructures. This article presents a quantum algorithm that has a linear scaling with respect to the number of atoms, which is much smaller than the number of electrons. Our algorithm leverages the quantum singular value transformation (QSVT) to generate a quantum circuit to encode the density-matrix, and an estimation method for computing the output electron density. In addition, we present a randomized block coordinate fixed-point method to accelerate the self-consistent field calculations by reducing the number of components of the electron density that needs to be estimated. The proposed framework is accompanied by a rigorous error analysis that quantifies the function approximation error, the statistical fluctuation, and the iteration complexity. In particular, the analysis of our self-consistent iterations takes into account the measurement noise from the quantum circuit. These advancements offer a promising avenue for tackling large-scale DFT problems, enabling simulations of complex systems that were previously computationally infeasible.
75.
Guoding Liu, Ziyi Xie, Zitai Xu, Xiongfeng Ma
Group Twirling and Noise Tailoring for Multi-Qubit-Controlled Phase Gates Poster
2024.
Abstract | Tags: Poster session Monday | Links:
@Poster{P24_49,
title = {Group Twirling and Noise Tailoring for Multi-Qubit-Controlled Phase Gates},
author = {Guoding Liu and Ziyi Xie and Zitai Xu and Xiongfeng Ma},
url = {https://arxiv.org/abs/2309.15651},
year = {2024},
date = {2024-01-01},
abstract = {Group twirling is crucial in quantum information processing, particularly in randomized benchmarking and randomized compiling. While protocols based on Pauli twirling have been effectively crafted to transform arbitrary noise channels into Pauli channels for Clifford gates — thereby facilitating efficient benchmarking and mitigating worst-case errors — the lack of practical twirling groups for multi-qubit non-Clifford gates remains a challenge. To address this gap, we study the issue of finding twirling groups for generic quantum gates, focusing on a widely used circuit structure in randomized benchmarking or randomized compiling. Specifically, for multi-qubit-controlled phase gates, which are essential in quantum algorithms and directly implementable in practice, we determine optimal twirling groups within the realm of classically replaceable unitary operations. Contrasting with the local Pauli twirling group for Clifford gates, the optimal groups for such gates contain nonlocal operations, highlighting the overhead of tailoring noise in global non-Clifford contexts. We design new benchmarking procedures for multi-qubit controlled phase gates based on the optimal twirling groups. Our simulation results show that our scheme can improve the precision and accuracy of benchmarking in small-scale systems.},
keywords = {Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
Group twirling is crucial in quantum information processing, particularly in randomized benchmarking and randomized compiling. While protocols based on Pauli twirling have been effectively crafted to transform arbitrary noise channels into Pauli channels for Clifford gates — thereby facilitating efficient benchmarking and mitigating worst-case errors — the lack of practical twirling groups for multi-qubit non-Clifford gates remains a challenge. To address this gap, we study the issue of finding twirling groups for generic quantum gates, focusing on a widely used circuit structure in randomized benchmarking or randomized compiling. Specifically, for multi-qubit-controlled phase gates, which are essential in quantum algorithms and directly implementable in practice, we determine optimal twirling groups within the realm of classically replaceable unitary operations. Contrasting with the local Pauli twirling group for Clifford gates, the optimal groups for such gates contain nonlocal operations, highlighting the overhead of tailoring noise in global non-Clifford contexts. We design new benchmarking procedures for multi-qubit controlled phase gates based on the optimal twirling groups. Our simulation results show that our scheme can improve the precision and accuracy of benchmarking in small-scale systems.
76.
Harshdeep Singh, Sonjoy Majumder, Sabyashachi Mishra
H ̈uckel Molecular Orbital Theory on a Quantum Computer: A Scalable System-Agnostic Variational Implementation with Compact Encoding Poster
2024.
Tags: Poster session Monday
@Poster{P24_163,
title = {H ̈uckel Molecular Orbital Theory on a Quantum Computer: A Scalable System-Agnostic Variational Implementation with Compact Encoding},
author = {Harshdeep Singh and Sonjoy Majumder and Sabyashachi Mishra},
year = {2024},
date = {2024-01-01},
keywords = {Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
77.
Lidia Ruiz, Juan Carlos García Escartín
Heuristics for routing and wavelength assignment in hybrid networks with classical and quantum signals Poster
2024.
Abstract | Tags: Poster session Monday | Links:
@Poster{P24_224,
title = {Heuristics for routing and wavelength assignment in hybrid networks with classical and quantum signals},
author = {Lidia Ruiz and Juan Carlos García Escartín},
url = {https://arxiv.org/abs/2311.10474},
year = {2024},
date = {2024-01-01},
abstract = {Quantum Key Distribution has become a mature quantum technology that has outgrown dedicated links and is ready to be incorporated into the classical infrastructure. In this scenario with multiple potential nodes, it is crucial having efficient ways to allocate the network resources between all the potential users. We propose a simple method for routing and wavelength assignment in wavelength multiplexed networks in which classical and quantum channels coexist. The proposed heuristics take into account the specific requirements of quantum key distribution and focus on keeping at bay the contamination of the quantum channels by photons coming from the classical signals by non-linear processes, among others. These heuristics reduce the shared path between classical and quantum channels and improve the signal-to-noise ratio in the quantum channels, improving their quantum key rate. We compare the results to the usual classical RWA approach.},
keywords = {Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
Quantum Key Distribution has become a mature quantum technology that has outgrown dedicated links and is ready to be incorporated into the classical infrastructure. In this scenario with multiple potential nodes, it is crucial having efficient ways to allocate the network resources between all the potential users. We propose a simple method for routing and wavelength assignment in wavelength multiplexed networks in which classical and quantum channels coexist. The proposed heuristics take into account the specific requirements of quantum key distribution and focus on keeping at bay the contamination of the quantum channels by photons coming from the classical signals by non-linear processes, among others. These heuristics reduce the shared path between classical and quantum channels and improve the signal-to-noise ratio in the quantum channels, improving their quantum key rate. We compare the results to the usual classical RWA approach.
78.
Philip Taranto, Thomas Elliot, Simon Milz
Hidden Quantum Memory: Is Memory There When Somebody Looks? Poster
2024.
Tags: Poster session Monday
@Poster{P24_55,
title = {Hidden Quantum Memory: Is Memory There When Somebody Looks?},
author = {Philip Taranto and Thomas Elliot and Simon Milz},
year = {2024},
date = {2024-01-01},
keywords = {Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
79.
Petr Ivashkov, Gideon Uchehara, Liang Jiang, Derek Wang, Alireza Seif
High-fidelity, multi-qubit generalized measurements with dynamic circuits Poster
2024.
Abstract | Tags: Poster session Monday | Links:
@Poster{P24_122,
title = {High-fidelity, multi-qubit generalized measurements with dynamic circuits},
author = {Petr Ivashkov and Gideon Uchehara and Liang Jiang and Derek Wang and Alireza Seif},
url = {https://arxiv.org/abs/2312.14087},
year = {2024},
date = {2024-01-01},
abstract = {Generalized measurements, also called positive operator-valued measures (POVMs), can offer advantages over projective measurements in various quantum information tasks. Here, we realize a generalized measurement of one and two superconducting qubits with high fidelity and in a single experimental setting. To do so, we propose a hybrid method, the "Naimark-terminated binary tree," based on a hybridization of Naimark's dilation and binary tree techniques that leverages emerging hardware capabilities for mid-circuit measurements and feed-forward control. Furthermore, we showcase a highly effective use of approximate compiling to enhance POVM fidelity in noisy conditions. We argue that our hybrid method scales better toward larger system sizes than its constituent methods and demonstrate its advantage by performing detector tomography of symmetric, informationally complete POVM (SIC-POVM). Detector fidelity is further improved through a composite error mitigation strategy that incorporates twirling and a newly devised conditional readout error mitigation. Looking forward, we expect improvements in approximate compilation and hardware noise for dynamic circuits to enable generalized measurements of larger multi-qubit POVMs on superconducting qubits.},
keywords = {Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
Generalized measurements, also called positive operator-valued measures (POVMs), can offer advantages over projective measurements in various quantum information tasks. Here, we realize a generalized measurement of one and two superconducting qubits with high fidelity and in a single experimental setting. To do so, we propose a hybrid method, the "Naimark-terminated binary tree," based on a hybridization of Naimark's dilation and binary tree techniques that leverages emerging hardware capabilities for mid-circuit measurements and feed-forward control. Furthermore, we showcase a highly effective use of approximate compiling to enhance POVM fidelity in noisy conditions. We argue that our hybrid method scales better toward larger system sizes than its constituent methods and demonstrate its advantage by performing detector tomography of symmetric, informationally complete POVM (SIC-POVM). Detector fidelity is further improved through a composite error mitigation strategy that incorporates twirling and a newly devised conditional readout error mitigation. Looking forward, we expect improvements in approximate compilation and hardware noise for dynamic circuits to enable generalized measurements of larger multi-qubit POVMs on superconducting qubits.
80.
Mohammed Barhoush, Louis Salvail
How to Sign Quantum Messages Poster
2024.
Tags: Poster session Monday
@Poster{P24_193,
title = {How to Sign Quantum Messages},
author = {Mohammed Barhoush and Louis Salvail},
year = {2024},
date = {2024-01-01},
keywords = {Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
81.
Maria Flors Mor Ruiz, Wolfgang Dür
Influence of noise in entanglement-based quantum networks Poster
2024.
Tags: Poster session Monday
@Poster{P24_106,
title = {Influence of noise in entanglement-based quantum networks},
author = {Maria Flors Mor Ruiz and Wolfgang Dür},
year = {2024},
date = {2024-01-01},
keywords = {Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
82.
Mariami Gachechiladze, Prabhav Jain, Nikolai Miklin
Information causality as a tool for bounding the set of quantum correlations Poster
2024.
Tags: Outstanding Poster, Poster session Monday
@Poster{P24_109,
title = {Information causality as a tool for bounding the set of quantum correlations},
author = {Mariami Gachechiladze and Prabhav Jain and Nikolai Miklin},
year = {2024},
date = {2024-01-01},
keywords = {Outstanding Poster, Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
83.
Lorenzo Giannelli, Giulio Chiribella
Information-theoretic derivation of energy and speed bounds Poster
2024.
Tags: Poster session Monday
@Poster{P24_160,
title = {Information-theoretic derivation of energy and speed bounds},
author = {Lorenzo Giannelli and Giulio Chiribella},
year = {2024},
date = {2024-01-01},
keywords = {Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
84.
Saheli Mukherjee, Bivas Mallick, Sravani Yanamandra, Samyadeb Bhattacharya, Ananda Gopal Maity
Interplay between the Hilbert-space dimension of the control system and the memory induced by quantum Poster
2024.
Tags: Poster session Monday
@Poster{P24_169,
title = {Interplay between the Hilbert-space dimension of the control system and the memory induced by quantum},
author = {Saheli Mukherjee and Bivas Mallick and Sravani Yanamandra and Samyadeb Bhattacharya and Ananda Gopal Maity},
year = {2024},
date = {2024-01-01},
keywords = {Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
85.
Lorcan Conlon, Falk Eilenberger, Jin Ming Koh, Biveen Shajilal, Jasminder Sidhu, Ping Koy Lam, Syed Assad
Investigations into the attainability of the ultimate limits in quantum state discrimination Poster
2024.
Abstract | Tags: Poster session Monday | Links:
@Poster{P24_103,
title = {Investigations into the attainability of the ultimate limits in quantum state discrimination},
author = {Lorcan Conlon and Falk Eilenberger and Jin Ming Koh and Biveen Shajilal and Jasminder Sidhu and Ping Koy Lam and Syed Assad},
url = {https://arxiv.org/abs/2302.08882},
year = {2024},
date = {2024-01-01},
abstract = {One of the fundamental tenets of quantum mechanics is that non-orthogonal states cannot be distinguished perfectly. When distinguishing multiple copies of a mixed quantum state, a collective measurement, which generates entanglement between the different copies of the unknown state, can achieve a lower error probability than non-entangling measurements. The error probability that can be attained using a collective measurement on M copies of the unknown state is given by the M-copy Helstrom bound. In the limit where we can perform a collective measurement on asymptotically many copies of the quantum state, the quantum Chernoff bound gives the error exponent. We first examine the conditions for when collective measurements offer an advantage over non-entangling measurements. Surprisingly, we find that whether collective measurements offer an advantage or not can depend on the prior probabilities of the different states. Using this, we implement on a superconducting quantum computer, the first case of a collective measurement surpassing the limits set by non-entangling measurements [1].
We then examine the attainability of the quantum Chernoff bound. Specifically we ask whether the asymptotic error exponent can be reached with a measurement on any finite number of copies and at what rate does the error tend to the asymptotic limit. We find analytic expressions for the Helstrom bound for arbitrary many copies of the unknown state in several simple qubit examples. Using these analytic expressions, we investigate how the attainable error exponent changes as we allow collective measurements on finite numbers of copies of the quantum state. Finally, using parameterised quantum circuits, we investigate the necessary conditions to saturate the M-copy Helstrom bound [1] Conlon, L. O., Eilenberger, F., Lam, P. K. & Assad, S. M. Discriminating mixed qubit states with collective measurements. Communications Physics 6, 337 (2023).},
keywords = {Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
One of the fundamental tenets of quantum mechanics is that non-orthogonal states cannot be distinguished perfectly. When distinguishing multiple copies of a mixed quantum state, a collective measurement, which generates entanglement between the different copies of the unknown state, can achieve a lower error probability than non-entangling measurements. The error probability that can be attained using a collective measurement on M copies of the unknown state is given by the M-copy Helstrom bound. In the limit where we can perform a collective measurement on asymptotically many copies of the quantum state, the quantum Chernoff bound gives the error exponent. We first examine the conditions for when collective measurements offer an advantage over non-entangling measurements. Surprisingly, we find that whether collective measurements offer an advantage or not can depend on the prior probabilities of the different states. Using this, we implement on a superconducting quantum computer, the first case of a collective measurement surpassing the limits set by non-entangling measurements [1].
We then examine the attainability of the quantum Chernoff bound. Specifically we ask whether the asymptotic error exponent can be reached with a measurement on any finite number of copies and at what rate does the error tend to the asymptotic limit. We find analytic expressions for the Helstrom bound for arbitrary many copies of the unknown state in several simple qubit examples. Using these analytic expressions, we investigate how the attainable error exponent changes as we allow collective measurements on finite numbers of copies of the quantum state. Finally, using parameterised quantum circuits, we investigate the necessary conditions to saturate the M-copy Helstrom bound [1] Conlon, L. O., Eilenberger, F., Lam, P. K. & Assad, S. M. Discriminating mixed qubit states with collective measurements. Communications Physics 6, 337 (2023).
We then examine the attainability of the quantum Chernoff bound. Specifically we ask whether the asymptotic error exponent can be reached with a measurement on any finite number of copies and at what rate does the error tend to the asymptotic limit. We find analytic expressions for the Helstrom bound for arbitrary many copies of the unknown state in several simple qubit examples. Using these analytic expressions, we investigate how the attainable error exponent changes as we allow collective measurements on finite numbers of copies of the quantum state. Finally, using parameterised quantum circuits, we investigate the necessary conditions to saturate the M-copy Helstrom bound [1] Conlon, L. O., Eilenberger, F., Lam, P. K. & Assad, S. M. Discriminating mixed qubit states with collective measurements. Communications Physics 6, 337 (2023).
86.
Timo Eckstein, Refik Mansuroglu, Piotr Czarnik, Jian-Xin Zhu, Michael Hartmann, Lukasz Cincio, Andrew Sornborger, Zoe Holmes
Large-scale simulations of Floquet physics on near-term quantum computers Poster
2024.
Tags: Poster session Monday
@Poster{P24_270,
title = {Large-scale simulations of Floquet physics on near-term quantum computers},
author = {Timo Eckstein and Refik Mansuroglu and Piotr Czarnik and Jian-Xin Zhu and Michael Hartmann and Lukasz Cincio and Andrew Sornborger and Zoe Holmes},
year = {2024},
date = {2024-01-01},
keywords = {Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
87.
Chirag Wadhwa, Mina Doosti
Learning Quantum Processes with Quantum Statistical Queries Poster
2024.
Tags: Poster session Monday
@Poster{P24_24,
title = {Learning Quantum Processes with Quantum Statistical Queries},
author = {Chirag Wadhwa and Mina Doosti},
year = {2024},
date = {2024-01-01},
keywords = {Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
88.
Haimeng Zhao, Laura Lewis, Ishaan Kannan, Yihui Quek, Hsin-Yuan Huang, Matthias Caro
Learning quantum states and unitaries of bounded gate complexity Poster
2024.
Abstract | Tags: Poster session Monday | Links:
@Poster{P24_239,
title = {Learning quantum states and unitaries of bounded gate complexity},
author = {Haimeng Zhao and Laura Lewis and Ishaan Kannan and Yihui Quek and Hsin-Yuan Huang and Matthias Caro},
url = {https://arxiv.org/abs/2310.19882},
year = {2024},
date = {2024-01-01},
abstract = {While quantum state tomography is notoriously hard, most states hold little interest to practically-minded tomographers. Given that states and unitaries appearing in Nature are of bounded gate complexity, it is natural to ask if efficient learning becomes possible. In this work, we prove that to learn a state generated by a quantum circuit with G two-qubit gates to a small trace distance, a sample complexity scaling linearly in G is necessary and sufficient. We also prove that the optimal query complexity to learn a unitary generated by G gates to a small average-case error scales linearly in G. While sample-efficient learning can be achieved, we show that under reasonable cryptographic conjectures, the computational complexity for learning states and unitaries of gate complexity G must scale exponentially in G. We illustrate how these results establish fundamental limitations on the expressivity of quantum machine learning models and provide new perspectives on no-free-lunch theorems in unitary learning. Together, our results answer how the complexity of learning quantum states and unitaries relate to the complexity of creating these states and unitaries.},
keywords = {Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
While quantum state tomography is notoriously hard, most states hold little interest to practically-minded tomographers. Given that states and unitaries appearing in Nature are of bounded gate complexity, it is natural to ask if efficient learning becomes possible. In this work, we prove that to learn a state generated by a quantum circuit with G two-qubit gates to a small trace distance, a sample complexity scaling linearly in G is necessary and sufficient. We also prove that the optimal query complexity to learn a unitary generated by G gates to a small average-case error scales linearly in G. While sample-efficient learning can be achieved, we show that under reasonable cryptographic conjectures, the computational complexity for learning states and unitaries of gate complexity G must scale exponentially in G. We illustrate how these results establish fundamental limitations on the expressivity of quantum machine learning models and provide new perspectives on no-free-lunch theorems in unitary learning. Together, our results answer how the complexity of learning quantum states and unitaries relate to the complexity of creating these states and unitaries.
89.
Soumyakanti Bose, Jaskaran Singh, Adan Cabello, Hyunseok Jeong
Long-distance entanglement sharing using hybrid states of discrete and continuous variables Poster
2024.
Tags: Poster session Monday
@Poster{P24_133,
title = {Long-distance entanglement sharing using hybrid states of discrete and continuous variables},
author = {Soumyakanti Bose and Jaskaran Singh and Adan Cabello and Hyunseok Jeong},
year = {2024},
date = {2024-01-01},
keywords = {Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
90.
Llorenç Escolà-Farràs, Florian Speelman
Lossy-and-Constrained Extended Non-Local Games with Applications to Cryptography: BC, QKD and QPV Poster
2024.
Tags: Poster session Monday
@Poster{P24_175,
title = {Lossy-and-Constrained Extended Non-Local Games with Applications to Cryptography: BC, QKD and QPV},
author = {Llorenç Escolà-Farràs and Florian Speelman},
year = {2024},
date = {2024-01-01},
keywords = {Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
91.
Nikhil Mande, Changpeng Shao
Lower bounds for quantum-inspired classical algorithms via communication complexity Poster
2024.
Tags: Poster session Monday
@Poster{P24_91,
title = {Lower bounds for quantum-inspired classical algorithms via communication complexity},
author = {Nikhil Mande and Changpeng Shao},
year = {2024},
date = {2024-01-01},
keywords = {Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
92.
Jordi Weggemans
Lower Bounds for Unitary Property Testing with Proofs and Advice Poster
2024.
Abstract | Tags: Poster session Monday | Links:
@Poster{P24_51,
title = {Lower Bounds for Unitary Property Testing with Proofs and Advice},
author = {Jordi Weggemans},
url = {https://arxiv.org/abs/2401.07912},
year = {2024},
date = {2024-01-01},
abstract = {In unitary property testing a quantum algorithm, also known as a tester, is given query access to a black-box unitary and has to decide whether it satisfies some property. We propose a new technique for proving lower bounds on the quantum query complexity of unitary property testing and related problems, which utilises the connection between unitary property testing and unitary channel discrimination. The main advantage of this technique is that all obtained lower bounds hold for any C-tester with C contained in QMA(2)/qpoly, showing that even having access to textitboth (unentangled) quantum proofs and advice does not help for many unitary problems. We apply our technique to prove lower bounds for problems like quantum phase estimation, the entanglement entropy problem, quantum Gibbs sampling and more, removing all logarithmic factors in the lower bounds obtained by the sample-to-query lifting theorem of Wang and Zhang (2023). As a direct corollary, we show that there exist quantum oracles relative to which QMA(2) and QMA/qpoly do not contain SBQP and SBQP. The former shows that, at least in a black-box way, having unentangled quantum proofs does not help in solving problems that require high precision.},
keywords = {Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
In unitary property testing a quantum algorithm, also known as a tester, is given query access to a black-box unitary and has to decide whether it satisfies some property. We propose a new technique for proving lower bounds on the quantum query complexity of unitary property testing and related problems, which utilises the connection between unitary property testing and unitary channel discrimination. The main advantage of this technique is that all obtained lower bounds hold for any C-tester with C contained in QMA(2)/qpoly, showing that even having access to textitboth (unentangled) quantum proofs and advice does not help for many unitary problems. We apply our technique to prove lower bounds for problems like quantum phase estimation, the entanglement entropy problem, quantum Gibbs sampling and more, removing all logarithmic factors in the lower bounds obtained by the sample-to-query lifting theorem of Wang and Zhang (2023). As a direct corollary, we show that there exist quantum oracles relative to which QMA(2) and QMA/qpoly do not contain SBQP and SBQP. The former shows that, at least in a black-box way, having unentangled quantum proofs does not help in solving problems that require high precision.
93.
Alex May, Vahid Asadi, Eric Culf, Richard Cleve
Lower bounds on entanglement and quantum gates in non-local quantum computation Poster
2024.
Tags: Poster session Monday
@Poster{P24_141,
title = {Lower bounds on entanglement and quantum gates in non-local quantum computation},
author = {Alex May and Vahid Asadi and Eric Culf and Richard Cleve},
year = {2024},
date = {2024-01-01},
keywords = {Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
94.
Junjie Chen, Yuxuan Yan, You Zhou
Magic of quantum hypergraph states Poster
2024.
Abstract | Tags: Poster session Monday | Links:
@Poster{P24_256,
title = {Magic of quantum hypergraph states},
author = {Junjie Chen and Yuxuan Yan and You Zhou},
url = {https://quantum-journal.org/papers/q-2024-05-21-1351/},
year = {2024},
date = {2024-01-01},
abstract = {Magic, or nonstabilizerness, characterizes the deviation of a quantum state from the set of stabilizer states, playing a fundamental role in quantum state complexity and universal fault-tolerant quantum computing. However, analytical and numerical characterizations of magic are very challenging, especially for multi-qubit systems, even with a moderate qubit number. Here, we systemically and analytically investigate the magic resource of archetypal multipartite quantum states—quantum hypergraph states, which can be generated by multi-qubit controlled-phase gates encoded by hypergraphs. We first derive the magic formula in terms of the stabilizer R$mathrmacutee$nyi-α entropies for general quantum hypergraph states. If the average degree of the corresponding hypergraph is constant, we show that magic cannot reach the maximal value, i.e., the number of qubits $n$. Then, we investigate the statistical behaviors of random hypergraph states' magic and prove a concentration result, indicating that random hypergraph states typically reach the maximum magic. This also suggests an efficient way to generate maximal magic states with random diagonal circuits. Finally, we study hypergraph states with permutation symmetry, such as $3$-complete hypergraph states, where any three vertices are connected by a hyperedge. Counterintuitively, such states can only possess constant or even exponentially small magic for $alphageq 2$. Our study advances the understanding of multipartite quantum magic and could lead to applications in quantum computing and quantum many-body physics.},
keywords = {Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
Magic, or nonstabilizerness, characterizes the deviation of a quantum state from the set of stabilizer states, playing a fundamental role in quantum state complexity and universal fault-tolerant quantum computing. However, analytical and numerical characterizations of magic are very challenging, especially for multi-qubit systems, even with a moderate qubit number. Here, we systemically and analytically investigate the magic resource of archetypal multipartite quantum states—quantum hypergraph states, which can be generated by multi-qubit controlled-phase gates encoded by hypergraphs. We first derive the magic formula in terms of the stabilizer R$mathrmacutee$nyi-α entropies for general quantum hypergraph states. If the average degree of the corresponding hypergraph is constant, we show that magic cannot reach the maximal value, i.e., the number of qubits $n$. Then, we investigate the statistical behaviors of random hypergraph states' magic and prove a concentration result, indicating that random hypergraph states typically reach the maximum magic. This also suggests an efficient way to generate maximal magic states with random diagonal circuits. Finally, we study hypergraph states with permutation symmetry, such as $3$-complete hypergraph states, where any three vertices are connected by a hyperedge. Counterintuitively, such states can only possess constant or even exponentially small magic for $alphageq 2$. Our study advances the understanding of multipartite quantum magic and could lead to applications in quantum computing and quantum many-body physics.
95.
Andi Gu, Salvatore Oliviero, Lorenzo Leone
Magic-induced computational separation in entanglement theory Poster
2024.
Abstract | Tags: Poster session Monday | Links:
@Poster{P24_261,
title = {Magic-induced computational separation in entanglement theory},
author = {Andi Gu and Salvatore Oliviero and Lorenzo Leone},
url = {https://arxiv.org/abs/2403.19610 https://arxiv.org/abs/2403.14912},
year = {2024},
date = {2024-01-01},
abstract = {Entanglement serves as a foundational pillar in quantum information theory, delineating the boundary between what is classical and what is quantum. The common assumption is that higher entanglement corresponds to a greater degree of 'quantumness'. However, this folk belief is challenged by the fact that classically simulable operations, such as Clifford circuits, can create highly entangled states. The simulability of these states raises a question: what are the differences between 'low-magic' entanglement, and 'high-magic' entanglement? We answer this question in this work with a rigorous investigation into the role of magic in entanglement theory. We take an operational approach to understanding this relationship by studying tasks such as entanglement estimation, distillation and dilution. This approach reveals that magic has surprisingly strong implications for entanglement. Specifically, we find a sharp operational separation that splits Hilbert space into two distinct phases: the entanglement-dominated (ED) phase and magic-dominated (MD) phase. Roughly speaking, ED states have entanglement that significantly surpasses their magic, while MD states have magic that dominates their entanglement. The competition between the two resources in these two phases induces a computational phase separation between them: there are sample- and time-efficient quantum algorithms for almost any entanglement task on ED states, while these tasks are provably computationally intractable in the MD phase. To demonstrate the power of our results beyond entanglement theory, we highlight the relevance of our findings in many-body physics and topological error correction. Additionally, we offer simple theoretical explanations for phenomenological observations made in previous numerical studies using ED-MD phases.},
keywords = {Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
Entanglement serves as a foundational pillar in quantum information theory, delineating the boundary between what is classical and what is quantum. The common assumption is that higher entanglement corresponds to a greater degree of 'quantumness'. However, this folk belief is challenged by the fact that classically simulable operations, such as Clifford circuits, can create highly entangled states. The simulability of these states raises a question: what are the differences between 'low-magic' entanglement, and 'high-magic' entanglement? We answer this question in this work with a rigorous investigation into the role of magic in entanglement theory. We take an operational approach to understanding this relationship by studying tasks such as entanglement estimation, distillation and dilution. This approach reveals that magic has surprisingly strong implications for entanglement. Specifically, we find a sharp operational separation that splits Hilbert space into two distinct phases: the entanglement-dominated (ED) phase and magic-dominated (MD) phase. Roughly speaking, ED states have entanglement that significantly surpasses their magic, while MD states have magic that dominates their entanglement. The competition between the two resources in these two phases induces a computational phase separation between them: there are sample- and time-efficient quantum algorithms for almost any entanglement task on ED states, while these tasks are provably computationally intractable in the MD phase. To demonstrate the power of our results beyond entanglement theory, we highlight the relevance of our findings in many-body physics and topological error correction. Additionally, we offer simple theoretical explanations for phenomenological observations made in previous numerical studies using ED-MD phases.
96.
Erkka Haapasalo, Muhammad Usman Farooq, Tobias Fritz, Marco Tomamichel, Frits Verhagen
Majorization in large samples Poster
2024.
Abstract | Tags: Poster session Monday | Links:
@Poster{P24_149,
title = {Majorization in large samples},
author = {Erkka Haapasalo and Muhammad Usman Farooq and Tobias Fritz and Marco Tomamichel and Frits Verhagen},
url = {https://arxiv.org/abs/2301.07353},
year = {2024},
date = {2024-01-01},
abstract = {In order to assess the information content of a statistical experiment (a collection of classical or quantum states), we need to compare it to other experiments. This comparability is called majorization and, in the classical case, we arrive at matrix majorization and, in the quantum case, at quantum majorization between tuples of quantum states. We study comparison of statistical experiments aided by having many copies of the experiments (large-sample case) or having an extra experiment aiding the majorization (catalytic case). We give explicit sufficient and almost necessary conditions for matrix majorization in large samples using multi-party extensions of the Renyi divergences. We also see that varying support restrictions yield varying sets of these multi-party divergences relevant for majorization in large samples. As a direct quantum application, we are finally able to give a secure proof for the sufficient and necessary conditions for asymptotic thermal majorization between quantum states of a thermodynamic system. Full quantum majorization between quantum statistical experiments is still a daunting problem, but we find sufficient and almost necessary conditions for measurement majorization. This means that we can give conditions characterizing when a given pair of quantum states yield given classical outcomes in some POVM measurement in large enough samples. More general quantum majorization results require the study of multi-party quantum divergences. Thus, defining such divergences and investigating their properties remains as a very important agenda.},
keywords = {Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
In order to assess the information content of a statistical experiment (a collection of classical or quantum states), we need to compare it to other experiments. This comparability is called majorization and, in the classical case, we arrive at matrix majorization and, in the quantum case, at quantum majorization between tuples of quantum states. We study comparison of statistical experiments aided by having many copies of the experiments (large-sample case) or having an extra experiment aiding the majorization (catalytic case). We give explicit sufficient and almost necessary conditions for matrix majorization in large samples using multi-party extensions of the Renyi divergences. We also see that varying support restrictions yield varying sets of these multi-party divergences relevant for majorization in large samples. As a direct quantum application, we are finally able to give a secure proof for the sufficient and necessary conditions for asymptotic thermal majorization between quantum states of a thermodynamic system. Full quantum majorization between quantum statistical experiments is still a daunting problem, but we find sufficient and almost necessary conditions for measurement majorization. This means that we can give conditions characterizing when a given pair of quantum states yield given classical outcomes in some POVM measurement in large enough samples. More general quantum majorization results require the study of multi-party quantum divergences. Thus, defining such divergences and investigating their properties remains as a very important agenda.
97.
Siyuan Chen, Wei Xie, Kun Wang
Memory Effects in Quantum State Verification Poster
2024.
Tags: Poster session Monday
@Poster{P24_255,
title = {Memory Effects in Quantum State Verification},
author = {Siyuan Chen and Wei Xie and Kun Wang},
year = {2024},
date = {2024-01-01},
keywords = {Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
98.
Graeme Berk, Jayne Thompson, Mile Gu
Memory Minimal Predictive Models for Quantum Processes Poster
2024.
Abstract | Tags: Poster session Monday
@Poster{P24_159,
title = {Memory Minimal Predictive Models for Quantum Processes},
author = {Graeme Berk and Jayne Thompson and Mile Gu},
year = {2024},
date = {2024-01-01},
abstract = {What is the minimum quantity of information a model requires to predict a process faithfully? Minimal models saturating the memory constraints imposed by physics represent the 'Occam’s Razor’ for observed behavior, quantifying the minimal causal mechanisms needed for their explanation. We extend these concepts to the quantum regime. Leveraging a novel quantum model reduction principle which we call linear dependence of future morphs, we derive the q-transducer, which we prove to be the memory minimal quantum model of a quantum process. We show that an experimenter interacting with a quantum process can asymptotically obtain maximal predictive ability by learning the current state of the q-transducer. We devise a model reduction algorithm to find q-transducers, and argue for the potential of efficient implementation.},
keywords = {Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
What is the minimum quantity of information a model requires to predict a process faithfully? Minimal models saturating the memory constraints imposed by physics represent the 'Occam’s Razor’ for observed behavior, quantifying the minimal causal mechanisms needed for their explanation. We extend these concepts to the quantum regime. Leveraging a novel quantum model reduction principle which we call linear dependence of future morphs, we derive the q-transducer, which we prove to be the memory minimal quantum model of a quantum process. We show that an experimenter interacting with a quantum process can asymptotically obtain maximal predictive ability by learning the current state of the q-transducer. We devise a model reduction algorithm to find q-transducers, and argue for the potential of efficient implementation.
99.
James Mills, Alexia Salavrakos, Rawad Mezher
Mitigating photon loss in linear optical quantum circuits' Merged with 'An error-mitigated photonic quantum circuit Born machine' Poster
2024.
Tags: Poster session Monday
@Poster{P24_172,
title = {Mitigating photon loss in linear optical quantum circuits' Merged with 'An error-mitigated photonic quantum circuit Born machine'},
author = {James Mills and Alexia Salavrakos and Rawad Mezher},
year = {2024},
date = {2024-01-01},
keywords = {Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
100.
Zohar Schwartzman-Nowik, Liran Shirizly, Haggai Landa
Modeling error correction with Lindblad dynamics and approximate channels Poster
2024.
Abstract | Tags: Poster session Monday | Links:
@Poster{P24_197,
title = {Modeling error correction with Lindblad dynamics and approximate channels},
author = {Zohar Schwartzman-Nowik and Liran Shirizly and Haggai Landa},
url = {https://arxiv.org/pdf/2402.16727},
year = {2024},
date = {2024-01-01},
abstract = {We analyze the performance of a quantum error correction code subject to physically motivated noise modeled by a Lindblad master equation. Working within the code-capacity framework, we consider a noise model including dissipative and coherent single-qubit terms and two-qubit crosstalk, studying how well different approximations of the noise capture the performance of the five-qubit code. We find that a composite-channel approximation where every noise term is considered separately, can capture the behavior in many physical cases up to relatively long timescales. Single-qubit approximations do not manage to properly capture the error correction dynamics with two-qubit noise, even for short times. A Pauli approximation going beyond a single-qubit channel, works well in many cases at short timescales relative to the noise strength, after which it eventually fails. We calculate the code pseudo-threshold emerging within this approach, and demonstrate how knowledge of the qubit parameters and connectivity can be used to design better decoders. These results shed light on the performance of error correction codes in the presence of realistic noise and can advance the ongoing efforts toward useful quantum error correction.},
keywords = {Poster session Monday},
pubstate = {published},
tppubtype = {Poster}
}
We analyze the performance of a quantum error correction code subject to physically motivated noise modeled by a Lindblad master equation. Working within the code-capacity framework, we consider a noise model including dissipative and coherent single-qubit terms and two-qubit crosstalk, studying how well different approximations of the noise capture the performance of the five-qubit code. We find that a composite-channel approximation where every noise term is considered separately, can capture the behavior in many physical cases up to relatively long timescales. Single-qubit approximations do not manage to properly capture the error correction dynamics with two-qubit noise, even for short times. A Pauli approximation going beyond a single-qubit channel, works well in many cases at short timescales relative to the noise strength, after which it eventually fails. We calculate the code pseudo-threshold emerging within this approach, and demonstrate how knowledge of the qubit parameters and connectivity can be used to design better decoders. These results shed light on the performance of error correction codes in the presence of realistic noise and can advance the ongoing efforts toward useful quantum error correction.
