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We study the problem of transmission of classical messages through a quantum channel in several network scenarios in the one-shot setting. We consider both the entanglement assisted and unassisted cases for the point to point quantum…

Quantum Physics · Physics 2019-03-19 Anurag Anshu , Rahul Jain , Naqueeb Ahmad Warsi

The capability of a given channel to communicate information is, a priori, distinct from its capability to distribute shared randomness. In this article we define randomness distribution capacities of quantum channels assisted by forward,…

Quantum Physics · Physics 2018-05-22 Raul Garcia-Patron , William Matthews , Andreas Winter

We introduce various measures of forward classical communication for bipartite quantum channels. Since a point-to-point channel is a special case of a bipartite channel, the measures reduce to measures of classical communication for…

Quantum Physics · Physics 2023-04-25 Dawei Ding , Sumeet Khatri , Yihui Quek , Peter W. Shor , Xin Wang , Mark M. Wilde

Understanding quantum channels and the strange behavior of their capacities is a key objective of quantum information theory. Here we study a remarkably simple, low-dimensional, single-parameter family of quantum channels with exotic…

Quantum Physics · Physics 2023-06-14 Felix Leditzky , Debbie Leung , Vikesh Siddhu , Graeme Smith , John A. Smolin

In quantum communication protocols the existence of a shared reference frame between two spatially separated parties is normally presumed. However, in many practical situations we are faced with the problem of misaligned reference frames.…

Quantum Physics · Physics 2016-12-01 Mehdi Ahmadi , Alexander R. H. Smith , Andrzej Dragan

Being attracted by the property of classical polar code, researchers are trying to find its analogue in quantum fields, which is called quantum polar code. The first step and the key to design quantum polar code is to find out for the…

Quantum Physics · Physics 2022-03-25 Zhengzhong Yi , Zhipeng Liang , Xuan Wang

Noisy quantum channels may be used in many information carrying applications. We show that different applications may result in different channel capacities. Upper bounds on several of these capacities are proved. These bounds are based on…

Quantum Physics · Physics 2009-10-30 Howard Barnum , M. A. Nielsen , Benjamin Schumacher

The unique and often-weird properties of quantum mechanics allow an information carrier to propagate through multiple trajectories of quantum channels simultaneously. This ultimately leads us to quantum trajectories with an indefinite…

Quantum Physics · Physics 2021-10-22 Daryus Chandra , Marcello Caleffi , Angela Sara Cacciapuoti

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

Classical communication capacity of a channel can be enhanced either through a device called a 'quantum switch' or by putting the channel in a quantum superposition. The gains in the two cases, although different, have their origin in the…

Quantum Physics · Physics 2020-01-27 Nicolas Loizeau , Alexei Grinbaum

We give a capacity formula for the classical information transmission over a noisy quantum channel, with separable encoding by the sender and limited resources provided by the receiver's pre-shared ancilla. Instead of a pure state, we…

Quantum Physics · Physics 2017-05-22 Quntao Zhuang , Elton Yechao Zhu , Peter W. Shor

Any physical process can be represented as a quantum channel mapping an initial state to a final state. Hence it can be characterized from the point of view of communication theory, i.e., in terms of its ability to transfer information.…

Quantum Physics · Physics 2014-12-16 F. Caruso , V. Giovannetti , C. Lupo , S. Mancini

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

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

We study the four well-known capacities of a two-parameter family of qubit Pauli channels. These are the channels which are covariant under the SO(2) group and contain the depolarizing channel as a special case. We find exact expressions…

Quantum Physics · Physics 2023-09-01 Abbas Poshtvan , Vahid Karimipour

We study classical capacities of quantum multi-access channels in geometric terms revealing breaking of additivity of Holevo-like capacity. This effect is purely quantum since, as one points out, any classical multi-access channels have…

Quantum Physics · Physics 2013-05-29 Lukasz Czekaj , Pawel Horodecki

Recent studies have shown that quantum information may be effectively transmitted by a finite collection of completely depolarizing channels in a coherent superposition of different orders, via an operation known as the quantum $\tt…

Quantum Physics · Physics 2024-07-04 Zhen Wu , James Fullwood , Zhihao Ma , Siqi Zhou , Qi Zhao , Giulio Chiribella

Coding theorems in quantum Shannon theory express the ultimate rates at which a sender can transmit information over a noisy quantum channel. More often than not, the known formulas expressing these transmission rates are intractable,…

Quantum Physics · Physics 2010-06-15 Kamil Bradler , Patrick Hayden , Dave Touchette , Mark M. Wilde

We introduce the concept of quasi-inverse of quantum and classical channels, prove general properties of these inverses and determine them for a large class of channels acting in an arbitrary finite dimension. Therefore we extend the…

Quantum Physics · Physics 2021-08-11 Fereshte Shahbeigi , Koorosh Sadri , Morteza Moradi , Karol Życzkowski , Vahid Karimipour

The possibility of stochastic resonance of a quantum channel and hence the noise enhanced quantum channel capacity is explored by considering one-Pauli channels which are more classical like. The fidelity of the channel is also considered.

Quantum Physics · Physics 2015-06-26 Julian Juhi-Lian Ting