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Quantum capacity, as the ultimate transmission rate of quantum communication, is characterized by regularized coherent information. In this work, we reformulate approximations of the quantum capacity by operator space norms and give both…

Quantum Physics · Physics 2019-11-06 Li Gao , Marius Junge , Nicholas LaRacuente

There have been several upper bounds on the quantum capacity of the single-mode Gaussian channels with thermal noise, such as thermal attenuator and amplifier. We consider a class of attenuator and amplifier with more general noises,…

Quantum Physics · Physics 2019-05-21 Youngrong Lim , Soojoon Lee , Jaewan Kim , Kabgyun Jeong

Single photons are the flying qubits of choice for distributing entanglement in a quantum internet. Quantum memories embedded in quantum repeaters are crucial to overcome transmission loss and enhance the rate of quantum communication. A…

Quantum Physics · Physics 2026-03-03 H. -X Luo , C. Li , J. -L. Ren , Y. Yuan , Y. -L. Wen , J. -F. Li , Y. -F. Wang , S. -C. Zhang , H. Yan , S. -L. Zhu

Designing encoding and decoding circuits to reliably send messages over many uses of a noisy channel is a central problem in communication theory. When studying the optimal transmission rates achievable with asymptotically vanishing error…

Quantum Physics · Physics 2024-11-07 Matthias Christandl , Alexander Müller-Hermes

We introduce a new quantum communication protocol for the transmission of quantum information under collective noise. Our protocol utilizes a decoherence-free subspace in such a way that an optimal asymptotic transmission rate is achieved,…

Quantum Physics · Physics 2013-01-18 Michael Skotiniotis , Wolfgang Dür , Barbara Kraus

The optimal rate at which information can be sent through a quantum channel when the transmitted signal must simultaneously carry some minimum amount of energy is characterized. To do so, we introduce the quantum-classical analogue of the…

Quantum Physics · Physics 2025-01-10 Bishal Kumar Das , Lav R. Varshney , Vaibhav Madhok

The capacity of noisy quantum channels characterizes the highest rate at which information can be reliably transmitted and it is therefore of practical as well as fundamental importance. Capacities of classical channels are computed using…

Quantum Physics · Physics 2021-07-02 Navneeth Ramakrishnan , Raban Iten , Volkher B. Scholz , Mario Berta

A model of quantum noisy channel with input encoding by a classical random vector is described. An equation of optimality is derived to determine a complete set of wave functions describing quantum decodings based on quasi-measurements…

Quantum Physics · Physics 2007-05-23 V. P. Belavkin , R. L. Stratonovich

Information must take up space, must weigh, and its flux must be limited. Quantum limits on communication and information storage leading to these conclusions are here described. Quantum channel capacity theory is reviewed for both steady…

Quantum Physics · Physics 2015-06-26 Jacob D. Bekenstein , Marcelo Schiffer

Quantum detectors provide information about quantum systems by establishing correlations between certain properties of those systems and a set of macroscopically distinct states of the corresponding measurement devices. A natural question…

Quantum Physics · Physics 2011-07-26 Ognyan Oreshkov , John Calsamiglia , Ramon Munoz-Tapia , Emili Bagan

Optical communication is the standard for high-bandwidth information transfer in today's digital age. The increasing demand for bandwidth has led to the maturation of coherent transceivers that use phase- and amplitude-modulated optical…

Quantum Physics · Physics 2024-09-24 John Crossman , Spencer Dimitroff , Lukasz Cincio , Mohan Sarovar

Superconducting quantum circuits, fabricated with multiple layers, are proposed to implement perfect quantum state transfer between nodes of a hypercube network. For tunable devices such as the phase qubit, each node can transmit quantum…

Quantum Physics · Physics 2009-11-13 Frederick W. Strauch , Carl J. Williams

We discover the quantum analog of the well-known classical maximum power transfer theorem. Our theoretical framework considers the continuous steady-state problem of coherent energy transfer through an N-node bosonic network coupled to an…

Quantum Physics · Physics 2019-04-19 Cristian L. Cortes , Zubin Jacob

We study the problem of joint communication and sensing for data transmission systems using optimal quantum instruments in order to transmit data and, at the same time, estimate environmental parameters. In particular we consider the…

Quantum Physics · Physics 2024-11-19 Pere Munar-Vallespir , Janis Nötzel

Quantum teleportation is essential for many quantum information technologies including long-distance quantum networks. Using fiber-coupled devices, including state-of-the-art low-noise superconducting nanowire single photon detectors and…

In this paper, cognitive transmission under quality of service (QoS) constraints is studied. In the cognitive radio channel model, it is assumed that the secondary transmitter sends the data at two different average power levels, depending…

Information Theory · Computer Science 2009-06-23 Sami Akin , Mustafa Cenk Gursoy

Quantum transduction converts quantum states between different frequencies. Similarly, quantum teleportation transfers quantum states between different systems. While often appreciated for quantum communication between distant locations,…

Quantum Physics · Physics 2026-01-30 Quntao Zhuang

Quantum channels can be activated by a kind of channels whose quantum capacity is zero. This activation effect might be useful to overcome noise of channels by attaching other channels which can enhance the capacity of a given channel. In…

Quantum Physics · Physics 2018-07-26 Youngrong Lim , Soojoon Lee

We investigate the quantum capacity of noisy quantum channels which can be represented by coupling a system to an effectively small environment. A capacity formula is derived for all cases where both system and environment are…

Quantum Physics · Physics 2009-11-13 Michael M. Wolf , David Perez-Garcia

We determine the ultimate classical information capacity of a linear time-invariant bosonic channel with additive phase-insensitive Gaussian noise. This channel can model fiber-optic communication at power levels below the threshold for…

Quantum Physics · Physics 2016-04-06 Bhaskar Roy Bardhan , Jeffrey H. Shapiro