English
Related papers

Related papers: The capacity of the quantum depolarizing channel

200 papers

The well-known duality relating entangled states and noisy quantum channels is expressed in terms of a channel ket, a pure state on a suitable tripartite system, which functions as a pre-probability allowing the calculation of statistical…

Quantum Physics · Physics 2009-11-10 Robert B. Griffiths

The thermodynamic resourcefulness of quantum channels primarily depends on their underlying causal structure and their ability to generate quantum correlations. We quantify this interplay within the resource theory of athermality for…

Quantum Physics · Physics 2026-04-02 Himanshu Badhani , Siddhartha Das

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

Classical messages can be sent via a noisy quantum channel in various ways, corresponding to various choices of signal states of the channel. Previous work by Holevo and by Schumacher and Westmoreland relates the capacity of the channel to…

Quantum Physics · Physics 2007-05-23 Benjamin Schumacher , Michael D. Westmoreland

Capacities of quantum channels and decoherence times both quantify the extent to which quantum information can withstand degradation by interactions with its environment. However, calculating capacities directly is known to be intractable…

Quantum Physics · Physics 2021-06-07 Ivan Bardet , Marius Junge , Nicholas LaRacuente , Cambyse Rouzé , Daniel Stilck França

We consider the problem of compression of the quantum information carried by ensemble of mixed states. We prove that for arbitrary coding schemes the least number of qubits needed to convey the signal states asymptotically faithfully is…

Quantum Physics · Physics 2009-10-30 Michal Horodecki

Optimization methods aimed at estimating the capacities of a general Gaussian channel are developed. Specifically evaluation of classical capacity as maximum of the Holevo information is pursued over all possible Gaussian encodings for the…

Quantum Physics · Physics 2012-09-12 Oleg V. Pilyavets , Cosmo Lupo , Stefano Mancini

Determining the ultimate classical information carrying capacity of electromagnetic waves requires quantum-mechanical analysis to properly account for the bosonic nature of these waves. Recent work has established capacity theorems for…

Quantum Physics · Physics 2008-02-10 Saikat Guha , Jeffrey H. Shapiro , Baris I. Erkmen

This paper concerns the capacity of the discrete noiseless channel introduced by Shannon. A sufficient condition is given for the capacity to be well-defined. For a general discrete noiseless channel allowing non-integer valued symbol…

Information Theory · Computer Science 2010-06-11 Georg Bocherer , Valdemar Cardoso da Rocha Junior , Cecilio Pimentel

We simplify some conjectures in quantum information theory; the additivity of minimal output entropy, the multiplicativity of maximal output p-norm and the superadditivity of convex closure of output entropy. We construct a unital channel…

Quantum Physics · Physics 2007-08-21 Motohisa Fukuda

When classical information is sent through a quantum channel of nonorthogonal states, there is a possibility that transmittable classical information exceeds a channel capacity in a single use of the initial channel by extending it into…

Quantum Physics · Physics 2009-10-30 Masahide Sasaki , Kentaro Kato , Masayuki Izutsu , Osamu Hirota

In this article we show that the Holevo capacity of a classical quantum channel, can be reached not only by a POVM but by von Neumann measurement too. Furthermore we show two use of this fact 1) We can generalize the classical compound…

Quantum Physics · Physics 2007-08-01 L. Farkas

We consider the image of some classes of bipartite quantum states under a tensor product of random quantum channels. Depending on natural assumptions that we make on the states, the eigenvalues of their outputs have new properties which we…

Mathematical Physics · Physics 2019-02-27 Benoit Collins , Motohisa Fukuda , Ion Nechita

High dimensional Hilbert spaces used for quantum communication channels offer the possibility of large data transmission capabilities. We propose a method of characterizing the channel capacity of an entangled photonic state in high…

Quantum Physics · Physics 2013-05-30 P. Ben Dixon , Gregory A. Howland , James Schneeloch , John C. Howell

In quantum Shannon theory, the way information is encoded and decoded takes advantage of the laws of quantum mechanics, while the way communication channels are interlinked is assumed to be classical. In this Letter we relax the assumption…

Quantum Physics · Physics 2018-03-28 Daniel Ebler , Sina Salek , Giulio Chiribella

The capacity of a channel with an energy-harvesting (EH) encoder and a finite battery remains an open problem, even in the noiseless case. A key instance of this scenario is the binary EH channel (BEHC), where the encoder has a unit-sized…

Information Theory · Computer Science 2025-02-12 Eli Shemuel , Oron Sabag , Haim H. Permuter

The present paper is devoted to investigation of the entropy reduction and entanglement-assisted classical capacity (information gain) of continuous variable quantum measurements. These quantities are computed explicitly for multimode…

Quantum Physics · Physics 2020-08-31 A. S. Holevo , A. A. Kuznetsova

A multiplicativity conjecture for quantum communication channels is formulated, validity of which for the values of parameter $p$ close to 1 is related to the solution of the fundamental problem of additivity of the channel capacity in…

Mathematical Physics · Physics 2007-05-23 G. G. Amosov , A. S. Holevo

In this work we design a specific simulation tool for quantum channels which is based on the use of a control system. This allows us to simulate an average quantum channel which is expressed in terms of an ensemble of channels, even when…

Quantum Physics · Physics 2018-12-19 Stefano Pirandola , Riccardo Laurenza , Leonardo Banchi

Quantum theory imposes fundamental limitations to the amount of information that can be carried by any quantum system. On the one hand, Holevo bound rules out the possibility to encode more information in a quantum system than in its…

Quantum Physics · Physics 2015-07-29 Michele Dall'Arno