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Related papers: Enhanced quantum capacity thresholds from symmetry

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We derive exact analytical expressions for the quantum capacity of a broad subclasses of generalized dephasing channels of the form $\Lambda(\rho)=(1-x)\rho + x D(\rho)$, where $D(\rho)$ represents a structured decoherence process. These…

Quantum Physics · Physics 2025-11-26 Shayan Roofeh , Vahid Karimipour

Long-distance optical quantum channels are necessarily lossy, leading to errors in transmitted quantum information, entanglement degradation and, ultimately, poor protocol performance. Quantum states carrying information in the channel can…

Completely depolarising channels are often regarded as the prototype of physical processes that are useless for communication: any message that passes through them along a well-defined trajectory is completely erased. When two such channels…

Quantum Physics · Physics 2021-11-10 Giulio Chiribella , Matt Wilson , H. F. Chau

A class of cognitive interference channel with state is investigated, in which two transmitters (transmitters 1 and 2) communicate with two receivers (receivers 1 and 2) over an interference channel. The two transmitters jointly transmit a…

Information Theory · Computer Science 2012-07-10 Ruchen Duan Yingbin Liang

Communication over a random-parameter quantum channel when the decoder is required to reconstruct the parameter sequence is considered. We study scenarios that include either strictly-causal, causal, or non-causal channel side information…

Information Theory · Computer Science 2021-09-28 Uzi Pereg

The applications of the general formulae of channel capacity developed in the quantum information theory to evaluation of information transmission capacity of optical channel are interesting subjects. In this review paper, we will point out…

Quantum Physics · Physics 2007-05-23 Masaki Sohma , Osamu Hirota

We study the properties of the quantum information transmission channel that emerges from the quantum dynamics of particles interacting with a black hole horizon. We calculate the quantum channel capacity in two limiting cases where a…

Quantum Physics · Physics 2014-08-20 Kamil Bradler , Christoph Adami

Quantum information theory is the study of the achievable limits of information processing within quantum mechanics. Many different types of information can be accommodated within quantum mechanics, including classical information, coherent…

Quantum Physics · Physics 2007-05-23 M. A. Nielsen

We consider the problem of transmitting classical and quantum information reliably over an entanglement-assisted quantum channel. Our main result is a capacity theorem that gives a three-dimensional achievable rate region. Points in the…

Quantum Physics · Physics 2010-08-23 Min-Hsiu Hsieh , Mark M. Wilde

Reciprocal pairs of quantum channels are defined as completely positive transformations which admit a rigid, distance-preserving, yet not completely-positive transformation that allows to reproduce the outcome of one from the corresponding…

Quantum Physics · Physics 2018-05-23 Matteo Rosati , Vittorio Giovannetti

Using the axiomatic definition of the coherence measure, such as the $l_{1}$ norm and the relative entropy, we study the phenomena of two-qubit system quantum coherence through quantum channels where successive uses of the channels are…

Quantum Physics · Physics 2016-12-30 You-neng Guo , Ke Zeng , Qing-long Tian , Zheng-da Li

The fragile nature of quantum information makes it practically impossible to completely isolate a quantum state from noise under quantum channel transmissions. Quantum networks are complex systems formed by the interconnection of quantum…

The additivity problem asks if the use of entanglement can boost the information-carrying capacity of a given channel beyond what is achievable by coding with simple product states only. This has recently been shown not to be the case for…

Quantum Physics · Physics 2018-04-10 Stefan Huber , Robert Koenig

Quantum amplifier channels are at the core of several physical processes. Not only do they model the optical process of spontaneous parametric down-conversion, but the transformation corresponding to an amplifier channel also describes the…

Quantum Physics · Physics 2017-02-02 Haoyu Qi , Mark M. Wilde

The classical product state capacity of a noisy quantum channel with memory is investigated. A forgetful noise-memory channel is constructed by Markov switching between two depolarizing channels which introduces non-Markovian noise…

Quantum Physics · Physics 2009-06-23 Jeroen Wouters , Ismail Akhalwaya , Mark Fannes , Francesco Petruccione

We present an experiment demonstrating entanglement-enhanced classical communication capacity of a quantum channel with correlated noise. The channel is modelled by a fiber optic link exhibiting random birefringence that fluctuates on a…

Quantum Physics · Physics 2007-05-23 K. Banaszek , A. Dragan , W. Wasilewski , C. Radzewicz

The possibility of stochastic resonance of a quantum channel and hence the noise enhanced capacity of the channel is explored by considering the depolarizing channel. The fidelity of the channel is also considered. Although there is no…

Statistical Mechanics · Physics 2007-05-23 Julian Juhi-Lian Ting

Quantum capacity gives the fundamental limit of information transmission through a channel. However, evaluating the quantum capacities of a continuous-variable bosonic quantum channel, as well as finding an optimal code to achieve the…

Quantum Physics · Physics 2025-10-03 Adam Taylor , Michael Hanks , Hyukjoon Kwon , M. S. Kim

The study of quantum channels is the fundamental field and promises wide range of applications, because any physical process can be represented as a quantum channel transforming an initial state into a final state. Inspired by the method…

Quantum Physics · Physics 2017-06-27 Shi-Jie Wei , Tao Xin , Gui-Lu Long

We construct a new entanglement-assisted quantum polar coding scheme which achieves the symmetric coherent information rate by synthesizing "amplitude" and "phase" channels from a given, arbitrary quantum channel. We first demonstrate the…

Quantum Physics · Physics 2012-09-04 Mark M. Wilde , Joseph M. Renes