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Related papers: Enhanced quantum capacity thresholds from symmetry

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The entanglement-assisted classical capacity of a noisy quantum channel is the amount of information per channel use that can be sent over the channel in the limit of many uses of the channel, assuming that the sender and receiver have…

Quantum Physics · Physics 2007-05-23 Charles H. Bennett , Peter W. Shor , John A. Smolin , Ashish V. Thapliyal

We analyze different aspects of multiparty communication over quantum memoryless channels and generalize some of key results known from bipartite channels to that of multiparty scenario. In particular, we introduce multiparty versions of…

Quantum Physics · Physics 2009-11-13 Maciej Demianowicz , Pawel Horodecki

Coherent information quantifies the achievable rate of the reliable quantum information transmission through a communication channel. Use of the correlated quantum states instead of the factorized ones may result in an increase in the…

Quantum Physics · Physics 2022-06-28 Sergey N. Filippov

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

Coherent information quantifies the transmittable quantum information through a channel and is directly linked to the channel's quantum capacity. In a monitored quantum circuit, regarded as a quantum channel, extensive and positive coherent…

Quantum Physics · Physics 2025-12-11 Dongheng Qian , Jing Wang

We analyze the quantum capacity of a unital quantum channel, using ideas from the proof of near-optimality of Petz recovery map [Barnum and Knill 2000] and give an upper bound on the quantum capacity in terms of regularized output $2$-norm…

Quantum Physics · Physics 2018-03-07 Anurag Anshu

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

We calculate the entanglement-assisted classical capacity of symmetric and asymmetric Pauli channels where two consecutive uses of the channels are correlated. It is evident from our study that in the presence of memory, a higher amount of…

Quantum Physics · Physics 2009-11-13 Nigum Arshed , A. H. Toor

A major challenge in quantum communication is addressing the negative effects of noise on channel capacity, especially for completely depolarizing channels, where information transmission is inherently impossible. The concept of indefinite…

Quantum communication theory focuses on the study of quantum channels for transmitting quantum information, where the transmission rate is measured by quantum channel capacity. This quantity exhibits several intriguing properties, such as…

Quantum Physics · Physics 2025-01-14 Changchun Zhong

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

The task of determining whether a given quantum channel has positive capacity to transmit quantum information is a fundamental open problem in quantum information theory. In general, the coherent information needs to be computed for an…

Quantum Physics · Physics 2022-08-17 Satvik Singh , Nilanjana Datta

We study a dephasing channel with memory, modelled by a multimode environment of oscillators. Focusing on the case of two channel uses, we show that memory effects can enhance the amount of coherent quantum information transmitted down the…

Quantum Physics · Physics 2008-06-18 A. D'Arrigo , G. Benenti , G. Falci

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…

For a continuous-input-continuous-output arbitrarily distributed quantum channel carrying classical information, the channel capacity can be computed in terms of the distribution of the channel envelope, received signal strength over a…

Information Theory · Computer Science 2022-06-09 Mouli Chakraborty , Harun Siljak , Indrakshi Dey , Nicola Marchetti

"Bounds on information combining" are entropic inequalities that determine how the information (entropy) of a set of random variables can change when these are combined in certain prescribed ways. Such bounds play an important role in…

Quantum Physics · Physics 2019-08-27 Christoph Hirche , David Reeb

We show the equivalence of two different notions of quantum channel capacity: that which uses the entanglement fidelity as its criterion of success in transmission, and that which uses the minimum fidelity of pure states in a subspace of…

Quantum Physics · Physics 2016-11-18 H. Barnum , E. Knill , M. A. Nielsen

Quantum information theory predicts that when the transmission resource is doubled in quantum channels, the amount of information transmitted can be increased more than twice by quantum channel coding technique, whereas the increase is at…

Quantum Physics · Physics 2009-11-10 M. Takeoka , M. Fujiwara , J. Mizuno , M. Sasaki

The quantum capacity of a quantum channel is always smaller than the capacity of the channel for private communication. However, both quantities are given by the infinite regularization of respectively the coherent and the private…

Quantum Physics · Physics 2015-07-28 David Elkouss , Sergii Strelchuk

The quantum capacity of thermal noise channel is studied. The extremal input state is obtained at the postulation that the coherent information is convex or concave at its vicinity. When the input energy tends to infinitive, it is verified…

Quantum Physics · Physics 2007-05-23 Xiao-yu Chen
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