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Related papers: Capacities of Quantum Erasure Channels

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Channel capacity describes the size of the nearly ideal channels, which can be obtained from many uses of a given channel, using an optimal error correcting code. In this paper we collect and compare minor and major variations in the…

Quantum Physics · Physics 2009-11-10 Dennis Kretschmann , Reinhard F Werner

Channel capacities of quantum channels can be nonadditive even if one of two quantum channels has no channel capacity. We call this phenomenon \emph{activation} of the channel capacity. In this paper, we show that when we use a quantum…

Quantum Physics · Physics 2018-06-29 Jeonghoon Park , Jun Heo

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

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

A formula for the capacity of a quantum channel for transmitting private classical information is derived. This is shown to be equal to the capacity of the channel for generating a secret key, and neither capacity is enhanced by forward…

Quantum Physics · Physics 2007-05-23 I. Devetak

We establish the classical capacity of optical quantum channels as a sharp transition between two regimes---one which is an error-free regime for communication rates below the capacity, and the other in which the probability of correctly…

Quantum Physics · Physics 2015-03-17 Bhaskar Roy Bardhan , Raul Garcia-Patron , Mark M. Wilde , Andreas Winter

The strong capacity of a particular channel can be interpreted as a sharp limit on the amount of information which can be transmitted reliably over that channel. To evaluate the strong capacity of a particular channel one must prove both…

Quantum Physics · Physics 2011-10-20 Tony Dorlas , Ciara Morgan

A strong converse theorem for channel capacity establishes that the error probability in any communication scheme for a given channel necessarily tends to one if the rate of communication exceeds the channel's capacity. Establishing such a…

Quantum Physics · Physics 2014-12-15 Mark M. Wilde , Andreas Winter

We study non-asymptotic fundamental limits for transmitting classical information over memoryless quantum channels, i.e. we investigate the amount of classical information that can be transmitted when a quantum channel is used a finite…

Quantum Physics · Physics 2015-05-20 Marco Tomamichel , Vincent Y. F. Tan

Determining whether a noisy quantum channel can be used to reliably transmit quantum information at a non-zero rate is a challenging problem in quantum information theory. This is because it requires computation of the channel's coherent…

Quantum Physics · Physics 2024-10-24 Satvik Singh , Nilanjana Datta

We prove the equivalence of an arbitrary single-mode Gaussian quantum channel and a newly defined fiducial channel preceded by a phase shift and followed by a Gaussian unitary operation. This equivalence implies that the energy-constrained…

We calculate the quantum capacity of an amplitude-damping channel with time correlated Markov noise, for two channel uses. Our results show that memory of the channel increases it's ability to transmit quantum information significantly. We…

Quantum Physics · Physics 2017-07-03 Rabia Jahangir , Nigum Arshed , A. H. Toor

We derive an analytical calculation formula for the channel capacity of a classical channel without any iteration while its existing algorithms require iterations and the number of iteration depends on the required precision level. Hence,…

Information Theory · Computer Science 2024-09-10 Masahito Hayashi

Quantum communications using continuous variables are quite mature experimental techniques and the relevant theories have been extensively investigated with various methods. In this paper, we study the continuous variable quantum channels…

Quantum Physics · Physics 2009-11-11 Tao Qin , Meisheng Zhao , Yongde Zhang

The information capacities and ``distillability'' of a quantum channel are studied in the presence of auxiliary resources. These include prior entanglement shared between the sender and receiver and free classical bits of forward and…

Quantum Physics · Physics 2009-11-10 Vittorio Giovannetti

The optimal rate at which information can be sent through a quantum channel when the transmitted signal must simultaneously carry some minimum amount of energy is characterized. To do so, we introduce the quantum-classical analogue of the…

Quantum Physics · Physics 2025-01-10 Bishal Kumar Das , Lav R. Varshney , Vaibhav Madhok

A family of quantum cloning machines is introduced that produce two approximate copies from a single quantum bit, while the overall input-to-output operation for each copy is a Pauli channel. A no-cloning inequality is derived, describing…

Quantum Physics · Physics 2009-10-31 Nicolas J. Cerf

We introduce potential capacities of quantum channels in an operational way and provide upper bounds for these quantities, which quantify the ultimate limit of usefulness of a channel for a given task in the best possible context.…

Quantum Physics · Physics 2016-02-17 Andreas Winter , Dong Yang

We determine the capacity of the classical compound quantum wiretapper channel with channel state information at the transmitter. Moreover we derive a lower bound on the capacity of this channel without channel state information and…

Quantum Physics · Physics 2012-02-06 Minglai Cai , Ning Cai , Christian Deppe

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