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Related papers: Capacities of Quantum Amplifier Channels

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We present a general model for quantum channels with memory, and show that it is sufficiently general to encompass all causal automata: any quantum process in which outputs up to some time t do not depend on inputs at times t' > t can be…

Quantum Physics · Physics 2009-11-11 Dennis Kretschmann , Reinhard F. Werner

The amount of information transmissible through a communications channel is determined by the noise characteristics of the channel and by the quantities of available transmission resources. In classical information theory, the amount of…

Quantum Physics · Physics 2009-11-10 Mikio Fujiwara , Masahiro Takeoka , Jun Mizuno , Masahide Sasaki

A quantum channel physically is a unitary interaction between the information carrying system and an environment, which is initialized in a pure state before the interaction. Conventionally, this state, as also the parameters of the…

Quantum Physics · Physics 2016-10-25 Siddharth Karumanchi , Stefano Mancini , Andreas Winter , Dong Yang

Arbitrarily varying channels offer a powerful framework for analyzing the robustness of quantum communication systems, especially for classical-quantum models, where the analysis displays strengths or weaknesses of specific signal…

Quantum Physics · Physics 2025-07-25 Janis Nötzel , Florian Seitz

Communication over a noisy channel is often conducted in a setting in which different input symbols to the channel incur a certain cost. For example, for bosonic quantum channels, the cost associated with an input state is the number of…

Quantum Physics · Physics 2018-12-27 Dawei Ding , Dmitri S. Pavlichin , Mark M. Wilde

High-performance quantum transducers, which faithfully convert quantum information between disparate physical carriers, are essential in quantum science and technology. Different figures of merit, including efficiency, bandwidth, and added…

Quantum Physics · Physics 2026-03-31 Chiao-Hsuan Wang , Fangxin Li , Liang Jiang

Thermal attenuator channels model the decoherence of quantum systems interacting with a thermal bath, e.g., a two-level system subject to thermal noise and an electromagnetic signal travelling through a fiber or in free-space. Hence…

Quantum Physics · Physics 2018-12-12 Matteo Rosati , Andrea Mari , Vittorio Giovannetti

In this article, we are proposing a closed-form solution for the capacity of the single quantum channel. The Gaussian distributed input has been considered for the analytical calculation of the capacity. In our previous couple of papers, we…

Information Theory · Computer Science 2023-02-17 Mouli Chakraborty , Harun Siljak , Indrakshi Dey , Nicola Marchetti

We consider all-optical network evolution from a quantum perspective. We show that a use of optimal quantum receivers allows an estimated $55\%$ decrease in energy consumption of all-optical amplifiers in network configurations that are…

Quantum Physics · Physics 2022-05-10 Janis Nötzel , Matteo Rosati

Quantum queue-channels arise naturally in the context of buffering in quantum networks, wherein the noise suffered by the quantum states depends on the time spent waiting in the buffer. It has been shown that the upper-bound on the…

In this article, we investigate the additivity phenomenon in the dynamic capacity of a quantum channel for trading classical communication, quantum communication and entanglement. Understanding such additivity property is important if we…

Quantum Physics · Physics 2017-08-17 Elton Yechao Zhu , Quntao Zhuang , Min-Hsiu Hsieh , Peter W. Shor

The quantum analog of the classical erasure channel provides a simple example of a channel whose asymptotic capacity for faithful transmission of intact quantum states, with and without the assistance of a two-way classical side channel,…

Quantum Physics · Physics 2008-11-26 Charles H. Bennett , David P. DiVincenzo , John A. Smolin

One of the major achievements of the recently emerged quantum information theory is the introduction and thorough investigation of the notion of quantum channel which is a basic building block of any data-transmitting or data-processing…

Quantum Physics · Physics 2012-03-23 A. S. Holevo , V. Giovannetti

A general quantum noisy channel is analyzed, wherein the transmitted qubits may experience symmetry-breaking decoherence, along with memory effects. We find the optimal basis not to be fully entangled, but a combination of factorized and…

Quantum Physics · Physics 2015-05-13 Goren Gordon , Gershon Kurizki

Following initial work by Gregoratti and Werner [J. Mod. Optics 50, 913-933, 2003 and quant-ph/0403092] and Hayden and King [quant-ph/0409026], we study the problem of the capacity of a quantum channel assisted by a "friendly (channel)…

Quantum Physics · Physics 2017-08-01 Andreas Winter

Classical feedback is defined here as the knowledge by the transmitter of the quantum state of the qubit received by the receiver. Such classical feedback doubles capacities of certain memoryless quantum channels without preexisting…

Quantum Physics · Physics 2007-05-23 Gleb V. Klimovitch

Encoding schemes and error-correcting codes are widely used in information technology to improve the reliability of data transmission over real-world communication channels. Quantum information protocols can further enhance the performance…

Capacities of quantum channels are fundamental quantities in the theory of quantum information. A desirable property is the additivity for a capacity. However, this cannot be achieved for a few quantities that have been established as…

Quantum Physics · Physics 2025-05-20 D. -S. Wang

Transmitting data reliably over noisy communication channels is one of the most important applications of information theory, and well understood when the channel is accurately modelled by classical physics. However, when quantum effects…

Quantum channel capacity is a fundamental quantity in order to understand how good can quantum information be transmitted or corrected when subjected to noise. However, it is generally not known how to compute such quantities, since the…

Quantum Physics · Physics 2023-09-20 Josu Etxezarreta Martinez , Antonio deMarti iOlius , Pedro M. Crespo