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Related papers: A decoupling approach to the quantum capacity

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The quantum capacity of a quantum channel captures its capability for noiseless quantum communication. It lies at the heart of quantum information theory. Unfortunately, our poor understanding of nonadditivity of coherent information makes…

Quantum Physics · Physics 2018-12-07 Felix Leditzky , Debbie Leung , Graeme Smith

Randomized measurements constitute a simple measurement primitive that exploits the information encoded in the outcome statistics of samples of local quantum measurements defined through randomly selected bases. In this work we exploit the…

Quantum Physics · Physics 2023-06-08 Sophia Ohnemus , Heinz-Peter Breuer , Andreas Ketterer

Quantum entanglement is an indispensable resource for many significant quantum information processing tasks. However, because of the noise in quantum channels, it is difficult to distribute quantum entanglement over a long distance in…

Quantum Physics · Physics 2018-01-31 Zhaofeng Su , Ji Guan , Lvzhou Li

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

Identification in quantum communication enables receivers to verify the presence of a message without decoding its entire content. While identification capacity has been explored for classical and finite-dimensional quantum channels, its…

Quantum Physics · Physics 2025-12-02 Zuhra Amiri , Janis Nötzel

In analogy with its classical counterpart, a noisy quantum channel is characterized by a loss, a quantity that depends on the channel input and the quantum operation performed by the channel. The loss reflects the transmission quality: if…

Quantum Physics · Physics 2011-07-19 Nicolas J. Cerf

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 propose and analyse a robust quantum state transfer protocol by the use of a combination of coherent quantum coupling and decoherence-free subspaces in a coupled quantum spin chain. Under decoherence, an arbitrary unknown quantum state…

Quantum Physics · Physics 2015-04-08 Wei Qin , Chuan Wang , Xiangdong Zhang

We consider the problem of creating a long-distance entangled state between two stations of a network, where neighboring nodes are connected by noisy quantum channels. We show that any two stations can share an entangled pair if the…

Quantum Physics · Physics 2009-01-19 S. Perseguers , L. Jiang , N. Schuch , F. Verstraete , M. D. Lukin , J. I. Cirac , K. G. H. Vollbrecht

The single-letter characterisation of the entanglement-assisted capacity of a quantum channel is one of the seminal results of quantum information theory. In this paper, we consider a modified communication scenario in which the receiver is…

Quantum Physics · Physics 2024-09-16 Kaiyuan Ji , Bartosz Regula , Mark M. Wilde

We introduce the concepts of cohering and de-cohering power of quantum channels. Using the axiomatic definition of coherence measure, we show that the optimizations required for calculations of these measures can be restricted to pure input…

Quantum Physics · Physics 2016-12-14 Azam Mani , Vahid Karimipour

We consider communication over a noisy network under randomized linear network coding. Possible error mechanism include node- or link- failures, Byzantine behavior of nodes, or an over-estimate of the network min-cut. Building on the work…

Information Theory · Computer Science 2007-11-27 Andrea Montanari , Ruediger Urbanke

Entanglement is one of the fundamental properties of a quantum state and is a crucial differentiator between classical and quantum computation. There are many ways to define entanglement and its measure, depending on the problem or…

Quantum Physics · Physics 2025-01-07 Andrii Semenov , Niall Murphy , Simone Patscheider , Alessandra Bernardi , Elena Blokhina

We analyze a task in which classical and quantum messages are simultaneously communicated via a noisy quantum channel, assisted with a limited amount of shared entanglement. We derive direct and converse bounds for the one-shot capacity…

Quantum Physics · Physics 2023-02-14 Eyuri Wakakuwa , Yoshifumi Nakata

We investigate prepare-and-measure scenarios in which a sender and a receiver use entanglement to send quantum information over a channel with limited capacity. We formalise this framework, identify its basic properties and provide…

Quantum Physics · Physics 2026-04-07 Elna Svegborn , Jef Pauwels , Armin Tavakoli

Accurately estimating high-order moments of quantum states is an elementary precondition for many crucial tasks in quantum computing, such as entanglement spectroscopy, entropy estimation, spectrum estimation, and predicting non-linear…

Quantum Physics · Physics 2024-05-16 Benchi Zhao , Mingrui Jing , Lei Zhang , Xuanqiang Zhao , Yu-Ao CHen , Kun Wang , Xin Wang

The resources needed to conventionally characterize a quantum system are overwhelmingly large for high- dimensional systems. This obstacle may be overcome by abandoning traditional cornerstones of quantum measurement, such as general…

Quantum Physics · Physics 2016-05-17 Gregory A. Howland , Samuel H. Knarr , James Schneeloch , Daniel J. Lum , John C. Howell

We experimentally demonstrate the achievement of the entanglement assisted capacity for classical information transmission over a depolarizing channel. The implementation is based on the generation and local manipulation of 2-qubit Bell…

Quantum Physics · Physics 2015-06-05 Andrea Chiuri , Sandro Giacomini , Chiara Macchiavello , Paolo Mataloni

The field of quantum communications promises the faithful distribution of quantum information, quantum entanglement, and absolutely secret keys, however, the highest rates of these tasks are fundamentally limited by the transmission…

Quantum Physics · Physics 2022-11-18 Matthew S. Winnel , Joshua J. Guanzon , Nedasadat Hosseinidehaj , Timothy C. Ralph

Typical quantum communication schemes are such that to achieve perfect decoding the receiver must share a reference frame with the sender. Indeed, if the receiver only possesses a bounded-size quantum token of the sender's reference frame,…

Quantum Physics · Physics 2009-06-09 Stephen D. Bartlett , Terry Rudolph , Robert W. Spekkens , Peter S. Turner
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