Article
Physics, Multidisciplinary
Qiming Ding, Quancheng Liu
Summary: In this paper, two no-go theorems for the deterministic purification and the probabilistic enhancement of coherence are presented. Feasibility criteria for these processes are provided, which have significant implications for understanding quantum coherence in real quantum systems.
JOURNAL OF PHYSICS A-MATHEMATICAL AND THEORETICAL
(2022)
Article
Physics, Multidisciplinary
Marwan Haddara, Eric G. Cavalcanti
Summary: The famous 'Wigner's friend' paradox explores the modeling of quantum systems under measurement when observers are subject to quantum mechanics. Recent research has found contradictions between the assumptions of 'Local Friendliness' and certain quantum phenomena. This study presents a probability-free version of the 'Local Friendliness' theorem using a modal logical approach, relying on a weaker assumption called 'Possibilistic Local Agency'.
NEW JOURNAL OF PHYSICS
(2023)
Article
Materials Science, Multidisciplinary
Pablo Parellada, Vicent Gimeno Garcia, Julio Jose Moyano-Fernandez, Juan Carlos Garcia-Escartin
Summary: We present a necessary condition for photon state transformations in linear optical setups that preserve the total number of photons. Through an analysis of the algebra describing quantum evolution, we identify a conserved quantity that appears in all permissible optical transformations. We provide examples, numerical applications, and give three general no-go results, including the impossibility of certain deterministic transformations and restrictions for converting between different types of entanglement.
RESULTS IN PHYSICS
(2023)
Article
Computer Science, Information Systems
Hao Cao, Wenping Ma, Liangdong Lue, Ge Liu, Xiaoxue Liu, Wenyang Sun
Summary: The paper presents a cryptanalysis of a quantum bit commitment (QBC) protocol proposed by Zhou et al., showing that the protocol is insecure due to its lack of binding property. An improved version of the protocol is proposed to meet security requirements.
INFORMATION SCIENCES
(2021)
Article
Quantum Science & Technology
Fabio Costa
Summary: This study shows that the order of two Markovian, unitary processes with equal local dimensions but different causal orders cannot be in a pure superposition, as it results in non-normalized probabilities when probed with specific operations. This result imposes constraints on novel resources for quantum information processing and possible processes in a theory of quantum gravity.
Article
Computer Science, Information Systems
Manal Khawasik, Wagdy Elsayed, Magdi Rashad, Ahmed Younes
Summary: This paper proposes a secured quantum two-bit commitment protocol for any two classical bits. The protocol utilizes different security layers to hide specific quantum states and applies secured unitary transformations to meet the concealing and binding conditions. The success of the protocol is verified by comparing the measured output.
Article
Physics, Multidisciplinary
Philippe Allard Guerin, Veronika Baumann, Flavio Del Santo, Caslav Brukner
Summary: This paper discusses a no-go theorem on the structure of probabilities in Wigner's friend thought experiment, and analyzes the validity of three particular assumptions in various interpretations of quantum mechanics.
COMMUNICATIONS PHYSICS
(2021)
Article
Astronomy & Astrophysics
Li Li, Run-Hua Shi
Summary: This paper presents a quantum bit commitment protocol that is simple, feasible, and practically secure without any spacetime constraint. The security of the proposed protocol is based on non-relativistic quantum mechanics and can resist all known attacks, including the Lo-Chau and Mayers attacks in practice.
MODERN PHYSICS LETTERS A
(2021)
Article
Optics
Zhen-Peng Xu, Jonathan Steinberg, H. Chau Nguyen, Otfried Guehne
Summary: The notion of measurements in quantum mechanics is a central topic of debate. It is questioned whether a measurement can be considered an absolute event that produces the same result for any observer in an irreversible manner. Through the use of Wigner's friend's gedanken experiment, it has been argued that assuming a measurement as an absolute event, in conjunction with the assumptions of locality and no superdeterminism, is incompatible with the universal validity of quantum mechanics. Another assumption, regarding whether a measurement event is realized relative to the observer when they only partially observe the outcome, is also shown to be incompatible with the universal validity of quantum mechanics when combined with the assumptions of no superdeterminism and locality.
Article
Optics
Sadegh Raeisi
Summary: This study demonstrates that the unitarity of compression operation imposes a cooling limit on heat-bath algorithmic cooling, introduces an optimal cooling technique, and shows that the limitations of unitarity lead to the exact cooling limit of algorithmic cooling.
Article
Computer Science, Hardware & Architecture
Lidong Xu, Mingqiang Wang, Jing Qin
Summary: This paper proposes a novel quantum bit commitment scheme that guarantees security without requiring quantum memory. The scheme utilizes coherent states and unambiguous state discrimination (USD) measurements, which can be implemented experimentally using linear optics and photon detectors. The unconditionally hiding and binding property is achieved by preventing complete information disclosure during the commitment stage and performing USD measurements and phase shifts immediately after receiving the coherent states.
Article
Psychology, Biological
Xiao Yang, Derek P. P. Spangler, J. Richard Jennings, Bruce H. H. Friedman
Summary: Sensorimotor responses are influenced by the phase of the cardiac cycle, known as cardiac cycle time effects. However, the validity of these effects is challenged by inconsistent findings. The current study examines the influence of cardiac cycle time and threatening stimuli on response speed and inhibition in an auditory Go/No-go task. Results suggest that cardiac timing modulates sensory-perceptual and attentional processes, and interacts with threatening contexts to influence response inhibition.
News Item
Physics, Multidisciplinary
Simone Gasparinetti
Summary: The emission of light from qubits in a superconducting circuit can be controlled to determine the direction of photon propagation, allowing for information routing in quantum networks.
Article
Physics, Multidisciplinary
Stephen Boughn
Summary: Einstein and many physicists were initially bothered by the collapse of the wave function in quantum mechanics, which seemed to violate the Schrodinger equation and special relativity. For the next few decades, wave function collapse was primarily discussed by philosophers until Bell introduced his famous inequality in 1964, bringing the topic back to mainstream physics. The apparent nonlocality of quantum mechanics continues to be a source of debate among physicists.
Article
Materials Science, Multidisciplinary
Guang Ping He
Summary: We propose a cheating strategy against a relativistic quantum commitment scheme (Nadeem, 2014) that claimed to be unconditionally secure. It is demonstrated that the sender Alice can cheat with a 100% success rate, thereby disproving the security claim.
RESULTS IN PHYSICS
(2023)
Editorial Material
Optics
Mohsen Razavi, Anthony Leverrier, Xiongfeng Ma, Bing Qi, Zhiliang Yuan
JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS
(2019)
Article
Physics, Multidisciplinary
Shouvik Ghorai, Philippe Grangier, Eleni Diamanti, Anthony Leverrier
Article
Computer Science, Hardware & Architecture
Omar Fawzi, Antoine Grospellier, Anthony Leverrier
Summary: The paper investigates the asymptotic scaling of space overhead required for fault-tolerant quantum computation, showing that the polylogarithmic factor in the standard threshold theorem is unnecessary. A fault-tolerant construction is proposed that only uses a constant factor more qubits than the ideal computation. This result challenges the traditional concatenated code approach and suggests using quantum error-correcting codes with a constant encoding rate.
COMMUNICATIONS OF THE ACM
(2021)
Article
Quantum Science & Technology
Daniele Dequal, Luis Trigo Vidarte, Victor Roman Rodriguez, Giuseppe Vallone, Paolo Villoresi, Anthony Leverrier, Eleni Diamanti
Summary: Establishing secure communication links at a global scale using quantum information science is challenging but achievable, as shown by recent landmark experiments. Continuous-variable encoding in a satellite-to-ground downlink configuration can lead to positive secret key rates, especially in low-Earth-orbit scenarios, with limitations potentially arising in higher orbits due to finite-size effects. Our analysis helps determine parameters for successful secret key exchange and can guide further experimental efforts in this direction.
NPJ QUANTUM INFORMATION
(2021)
Article
Quantum Science & Technology
Antoine Grospellier, Lucien Groues, Anirudh Krishna, Anthony Leverrier
Summary: This research introduces new hybrid decoders that combine the belief propagation algorithm with the small-set-flip (SSF) decoder to improve the decoding performance of quantum low-density parity-check (LDPC) codes. Numerical simulations show that the error threshold of these codes performs well under different conditions.
Article
Quantum Science & Technology
Aurelie Denys, Peter Brown, Anthony Leverrier
Summary: The study establishes an analytical lower bound for continuous-variable quantum key distribution, supporting efficient modulation schemes and proposing a solution suitable for large-scale deployment.
Article
Computer Science, Theory & Methods
Frederic Magniez, Ashwin Nayak
Summary: This research focuses on the number of rounds required for computing Set Disjointness in a distributed computing scenario with quantum processors, introducing the concept of "Set Disjointness on a Line" and providing an unconditional lower bound. It also connects the distributed computing scenario with a new query complexity model, demonstrating an algorithm for computing Set Disjointness in this model with round complexity matching the round lower bound.
ACM TRANSACTIONS ON COMPUTATION THEORY
(2022)
Article
Quantum Science & Technology
Anthony Leverrier, Simon Apers, Christophe Vuillot
Summary: This article introduces a variant of the three-dimensional hypergraph product code construction and explores the non-CSS quantum LDPC code and its related algebraic and combinatorial problems, aiming to find potential codes for self-correcting quantum memories.
Article
Quantum Science & Technology
Anthony Leverrier, Vivien Londe, Gilles Zemor
Summary: This study introduces a new family of quantum codes called hemicubic codes. These codes are obtained by associating qubits with the faces of the n-cube and stabilizer constraints with faces of dimension (p +/- 1). The resulting quantum codes display local testability and a decoding algorithm is developed to correct errors. The study also explores the extension of this code family by considering the quotient of the n-cube by arbitrary linear classical codes. These hemicubic codes have potential applications in quantum computing.
Proceedings Paper
Computer Science, Information Systems
Omar Fawzi, Lucien Groues, Anthony Leverrier
Summary: The decoder based on linear programming for quantum CSS codes has a different approach from previous definitions, but performs well in simulations, especially in hypergraph products, where it outperforms traditional methods.
2020 IEEE INFORMATION THEORY WORKSHOP (ITW)
(2021)
Proceedings Paper
Computer Science, Information Systems
Taisuke Izumi, Francois Le Gall, Frederic Magniez
37TH INTERNATIONAL SYMPOSIUM ON THEORETICAL ASPECTS OF COMPUTER SCIENCE (STACS 2020)
(2020)
Article
Computer Science, Theory & Methods
Vivien Londe, Anthony Leverrier
QUANTUM INFORMATION & COMPUTATION
(2019)
Article
Optics
Shouvik Ghorai, Eleni Diamanti, Anthony Leverrier
Proceedings Paper
Computer Science, Theory & Methods
Eldar Fischer, Frederic Magniez, Tatiana Starikovskaya
SODA'18: PROCEEDINGS OF THE TWENTY-NINTH ANNUAL ACM-SIAM SYMPOSIUM ON DISCRETE ALGORITHMS
(2018)
Proceedings Paper
Computer Science, Hardware & Architecture
Francois Le Gall, Frederic Magniez
PODC'18: PROCEEDINGS OF THE 2018 ACM SYMPOSIUM ON PRINCIPLES OF DISTRIBUTED COMPUTING
(2018)
