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Related papers: Hybrid Zero-capacity Channels

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We introduce an infinite sequence of quantum channels for which the Holevo capacity is additive. The channel series is closely related to the quantum channels arising from universal quantum cloning machines. The additivity proof is…

Quantum Physics · Physics 2016-11-17 Kamil Bradler

The most general quantum object that can be shared between two distant parties is a bipartite channel, as it is the basic element to construct all quantum circuits. In general, bipartite channels can produce entangled states, and can be…

Quantum Physics · Physics 2021-06-29 Gilad Gour , Carlo Maria Scandolo

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

Entanglement and entanglement-assisted are useful resources to enhance the mutual information of the Pauli channels, when the noise on consecutive uses of the channel has some partial correlations. In this Paper, we study…

Quantum Physics · Physics 2015-06-26 A. Fahmi , M. Golshani

It is well known that quantum theory forbids the exact copying of an unknown quantum state. Therefore in broadcasting of classical information by a quantum channel an additional contribution to the error in the decoding is expected. We…

Quantum Physics · Physics 2007-05-23 A. E. Allahverdyan , D. B. Saakian

We present an upper bound for the quantum channel capacity that is both additive and convex. Our bound can be interpreted as the capacity of a channel for high-fidelity quantum communication when assisted by a family of channels that have…

Quantum Physics · Physics 2008-08-28 Graeme Smith , John A. Smolin , Andreas Winter

The capacity of quantum channel with product input states was formulated by the quantum coding theorem. However, whether entangled input states can enhance the quantum channel is still open. It turns out that this problem is reduced to…

Quantum Physics · Physics 2007-05-23 Susumu Osawa , Hiroshi Nagaoka

An elementary introduction into algebraic approach to unified quantum information theory and operational approach to quantum entanglement as generalized encoding is given. After introducing compound quantum state and two types of…

Quantum Physics · Physics 2017-08-23 V. P. Belavkin , X. Dai

We determine the optimal rates of universal quantum codes for entanglement transmission and generation under channel uncertainty. In the simplest scenario the sender and receiver are provided merely with the information that the channel…

Quantum Physics · Physics 2015-05-13 I. Bjelakovic , H. Boche , J. Noetzel

We study the effects of quantum entanglement on the performance of two classical zero-error communication tasks among multiple parties. Both tasks are generalizations of the two-party zero-error channel-coding problem, where a sender and a…

Quantum Physics · Physics 2015-01-21 Teresa Piovesan , Giannicola Scarpa , Christian Schaffner

With progress in quantum technologies, the field of quantum networks has emerged as an important area of research. In the last few years, there has been substantial progress in understanding the correlations present in quantum networks. In…

Quantum Physics · Physics 2023-07-19 Manish Kumar Shukla , Minyi Huang , Indranil Chakrabarty , Junde Wu

Entangling an unknown qubit with one type of reference state is generally impossible. However, entangling an unknown qubit with two types of reference states is possible. To achieve this, we introduce a new class of states called zero sum…

Quantum Physics · Physics 2009-11-07 Arun Kumar Pati

Effective information transmission is a central element in quantum information protocols, but the quest for optimal efficiency in channels with symmetrical characteristics remains a prominent challenge in quantum information science. In…

Quantum Physics · Physics 2023-11-02 Atta ur Rahman , S. M. Zangi , Ma-Cheng Yang , Cong-Feng Qiao

All communication channels are at bottom quantum mechanical. Quantum mechanics contributes both obstacles to communication in the form of noise, and opportunities in the use of intrinsically quantum representations for information. This…

Quantum Physics · Physics 2007-05-23 Seth Lloyd

Communication over a noisy quantum channel introduces errors in the transmission that must be corrected. A fundamental bound on quantum error correction is the quantum capacity, which quantifies the amount of quantum data that can be…

Quantum Physics · Physics 2009-02-20 Graeme Smith , Jon Yard

A fully general strong converse for channel coding states that when the rate of sending classical information exceeds the capacity of a quantum channel, the probability of correctly decoding goes to zero exponentially in the number of…

Quantum Physics · Physics 2013-05-29 Robert Koenig , Stephanie Wehner

Entangled inputs can enhance the capacity of quantum channels, this being one of the consequences of the celebrated result showing the non-additivity of several quantities relevant for quantum information science. In this work, we answer…

Quantum Physics · Physics 2015-05-20 Fernando G. S. L. Brandao , Jens Eisert , Michal Horodecki , Dong Yang

We study various super-activation effects in the following zero-error communication scenario: One sender wants to send classical or quantum information through a noisy quantum channel to one receiver with zero probability of error. First we…

Quantum Physics · Physics 2009-06-16 Runyao Duan

We show that it is possible to achieve maximally entangled mixed states of two qubits from the singlet state via the action of local non-trace-preserving quantum channels. Moreover, we present a simple, feasible linear optical…

Quantum Physics · Physics 2007-05-23 A. Aiello , G. Puentes , D. Voigt , J. P. Woerdman

An entangled two-mode coherent state is studied within the framework of $2\times 2$ dimensional Hilbert space. An entanglement concentration scheme based on joint Bell-state measurements is worked out. When the entangled coherent state is…

Quantum Physics · Physics 2009-11-07 H. Jeong , M. S. Kim , Jinhyoung Lee