Article
Quantum Science & Technology
Jing Wu, Anthony J. Brady, Quntao Zhuang
Summary: In this work, we derive the optimal oscillator-to-oscillator codes for homogeneous noise, including the D4 lattice encoding for two-mode data and ancilla, which outperforms the product of lower dimensional lattices. Additionally, we prove a universal no-threshold-theorem for arbitrary oscillators-to-oscillators codes based on Gaussian encoding.
Article
Computer Science, Information Systems
Samad Khabbazi Oskouei, Stefano Mancini, Andreas Winter
Summary: Passive environment-assisted communication is investigated in terms of information transmission capabilities. Gaussian unitaries acting on Bosonic systems are considered for both quantum and classical communication. Coding theorems are proved, and an uncertainty-type relation between the classical capacities of the sender and the helper is derived, providing lower bounds on the classical information transmission rate.
IEEE TRANSACTIONS ON INFORMATION THEORY
(2022)
Article
Multidisciplinary Sciences
Vikesh Siddhu
Summary: This article explores the non-additivity of quantum channel coherent information, linking it to the log singularity of quantum entropy and discovering that non-additivity can occur even in low-noise channels. The author introduces and links logarithmic singularities in the von-Neumann entropy with quantum transmission, identifying mechanisms responsible for both positivity and non-additivity of the coherent information. A general theorem is proven concerning the positivity of a channel's coherent information, with applications solving open problems and characterizing qubit channels.
NATURE COMMUNICATIONS
(2021)
Article
Physics, Multidisciplinary
Felix Leditzky, Debbie Leung, Vikesh Siddhu, Graeme Smith, John A. Smolin
Summary: Determining capacities of quantum channels is a fundamental question in quantum information theory. The study of superadditivity effects in quantum channels is important for deepening our understanding of quantum information. In this research, the authors study a family of channels called platypus channels and show that they exhibit superadditivity of coherent information and quantum capacity when used jointly with other channels. The results demonstrate that superadditivity is more prevalent than previously thought and can occur between channels with large quantum capacity.
PHYSICAL REVIEW LETTERS
(2023)
Article
Computer Science, Information Systems
Yihan Zhang, Shashank Vatedka, Sidharth Jaggi, Anand D. Sarwate
Summary: In this study, we investigate communication in the presence of a jamming adversary with quadratic power constraints on the transmitter and the jammer. We characterize the capacity of this channel under different noise-to-signal ratios (NSRs) and discuss the assumption of common randomness between the encoder and decoder. Our proof techniques involve a myopic list-decoding result and a Plotkin-type push attack.
IEEE TRANSACTIONS ON INFORMATION THEORY
(2022)
Article
Quantum Science & Technology
Y. Lahlou, L. Bakmou, B. Maroufi, M. Daoud
Summary: In this study, we propose a scheme to investigate the dynamic evolution of quantum correlations in two-mode Gaussian states under the influence of a Gaussian thermal environment. By quantifying the Gaussian interferometric power and the Gaussian entanglement of formation, we find that the behavior of quantum correlations depends on the parameters of the input states, and the Gaussian interferometric power is less affected by the environment.
QUANTUM INFORMATION PROCESSING
(2022)
Article
Computer Science, Information Systems
Anas Chaaban, Zouheir Rezki, Mohamed-Slim Alouini
Summary: This tutorial provides an overview of the capacity results for intensity-modulation and direct-detection (IM/DD) channels used in optical wireless communication (OWC). It focuses on the capacity bounds for single-input single-output and multiple-input multiple-output systems.
IEEE COMMUNICATIONS SURVEYS AND TUTORIALS
(2022)
Article
Computer Science, Information Systems
Felix Leditzky, Debbie Leung, Vikesh Siddhu, Graeme Smith, John A. Smolin
Summary: Understanding quantum channels and their capacities is important in quantum information theory. This study focuses on a simple family of quantum channels with exotic features. The capabilities of these channels behave in interesting ways, such as having equal private and classical capacities. The quantum capacity can be explicitly computed with the assumption of a conjecture. The study also generalizes the channels and shows similar behavior in different cases.
IEEE TRANSACTIONS ON INFORMATION THEORY
(2023)
Article
Physics, Multidisciplinary
Arindam Mitra, Himanshu Badhani, Sibasish Ghosh
Summary: Applications of the quantum switch on quantum channels have been a hot topic. In this work, we find that some useless channels can provide useful communication under the action of a quantum switch for tasks like quantum random access codes and quantum steering. We also demonstrate the usefulness of the quantum switch in preventing coherence loss when only coherence-breaking channels are available. Furthermore, we show that by concatenating a useless channel with another suitable quantum channel and subsequently using the switch, useful communication can be achieved.
Article
Quantum Science & Technology
M. Fanizza, M. Rosati, M. Skotiniotis, J. Calsamiglia, V Giovannetti
Summary: The article explores the transmission of classical information using quantum Gaussian states on phase-noise channels with finite decoherence time, emphasizing the advantages of photon-number encodings and squeezed-coherent encodings, as well as the sub-optimality of using part of the energy to establish a reference frame. The results demonstrate the superiority of non-classical encoding methods in a communication setting.
Article
Quantum Science & Technology
Arthur O. T. Pang, Noah Lupu-Gladstein, Hugo Ferretti, Y. Batuhan Yilmaz, Aharon Brodutch, Aephraim M. Steinberg
Summary: Enhancing information capacity through coherent control of channels has recently garnered attention, with studies focusing on the effect of causal orders, channel superpositions, and information encoding. Expanding channel descriptions for superposing qubit channels, equivalent to acting on qutrits, has been shown to explain capacity enhancement without the need for superposition.
Article
Optics
Jeffrey H. Shapiro
Summary: This research proves that the error probability of a coherent-state radar is within a factor of two of the best possible quantum performance under certain conditions. However, first-photon radars can surpass this limit and achieve better performance.
Article
Optics
M. Vaisakh, Ram Krishna Patra, Mukta Janpandit, Samrat Sen, Manik Banik, Anubhav Chaturvedi
Summary: The study introduces a generalized random access code task where the receiver aims to retrieve randomly chosen functions of the sender's input string, in addition to individual input bits. The performance of classical, quantum, and entanglement assisted classical communication protocols for this task is investigated and bounded, revealing characteristic properties that deviate from standard random access codes.
Article
Physics, Multidisciplinary
Ming-Xiao Li, Zhu-Jun Zheng
Summary: The method of detecting lower bounds of the classical capacity of quantum channels is extended to two-qubit correlated channels in this paper. The efficiency of the scheme is demonstrated through examples involving the correlated dephasing channel, correlated depolarizing channel, and fully correlated amplitude damping channel.
EUROPEAN PHYSICAL JOURNAL PLUS
(2022)
Article
Physics, Multidisciplinary
Stefano Chessa, Vittorio Giovannetti
Summary: This article introduces multi-level amplitude damping channels that generalize concepts in quantum information theory to finite-dimensional quantum systems, and computes the quantum and private classical capacities associated with these channels. By exploiting degradability, data-processing inequalities, and channel isomorphism, the authors extend the set of models whose capacity can be computed known so far.
COMMUNICATIONS PHYSICS
(2021)
Article
Physics, Multidisciplinary
Marcus Appleby, Steven Flammia, Gary McConnell, Jon Yard
FOUNDATIONS OF PHYSICS
(2017)
Article
Computer Science, Information Systems
Jon Yard, Patrick Hayden, Igor Devetak
IEEE TRANSACTIONS ON INFORMATION THEORY
(2008)
Article
Computer Science, Information Systems
Jon T. Yard, Igor Devetak
IEEE TRANSACTIONS ON INFORMATION THEORY
(2009)
Article
Computer Science, Information Systems
Jon Yard, Patrick Hayden, Igor Devetak
IEEE TRANSACTIONS ON INFORMATION THEORY
(2011)
Article
Physics, Multidisciplinary
Igor Devetak, Jon Yard
PHYSICAL REVIEW LETTERS
(2008)
Article
Multidisciplinary Sciences
Graeme Smith, Jon Yard
Article
Mathematics
Marcus Appleby, Steven Flammia, Gary Mcconnell, Jon Yard
Proceedings Paper
Engineering, Electrical & Electronic
Jon Yard
2012 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO)
(2012)
Article
Physics, Multidisciplinary
David Poulin, Jon Yard
NEW JOURNAL OF PHYSICS
(2007)
