English
Related papers

Related papers: Coherent information analysis of quantum channels …

200 papers

Decoherence-free states protect quantum information from collective noise, the predominant cause of decoherence in current implementations of quantum communication and computation. Here we demonstrate that spontaneous parametric…

We exploit a novel approximation scheme to obtain a new and compact formula for the parameters underlying coherent-state control of the evolution of a pair of entangled two-level systems. It is appropriate for long times and for relatively…

Quantum Physics · Physics 2010-08-24 Muhammed Yonac , Joseph H. Eberly

Quantum systems can be controlled by other quantum systems in a reversible way, without any information leaking to the outside of the system-controller compound. Such coherent quantum control is deterministic, is less noisy than…

Quantum Physics · Physics 2021-12-28 Thomas Konrad , Amy Rouillard , Michael Kastner , Hermann Uys

We outline selected trends and results in theoretical modeling of quantum systems in support of the developing research field of quantum information processing. The resulting modeling tools have been applied to semiconductor materials and…

Mesoscale and Nanoscale Physics · Physics 2010-10-12 Vladimir Privman

A small superconducting electrode (a single-Cooper-pair box) connected to a reservoir via a Josephson junction constitutes an artificial two-level system, in which two charge states that differ by 2e are coupled by tunneling of Cooper…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 Y. Nakamura , Yu. A. Pashkin , J. S. Tsai

Coherence has been used as a resource for optical communications since its earliest days. It is widely used for multiplexing of data, but not for encoding of data. Here we introduce a coding scheme, which we call \textit{mutual coherence…

We develop a quantum learning scheme for binary discrimination of coherent states of light. This is a problem of technological relevance for the reading of information stored in a digital memory. In our setting, a coherent light source is…

Quantum Physics · Physics 2015-07-09 Gael Sentís , Madalin Guta , Gerardo Adesso

An extensively pursued current direction of research in physics aims at the development of practical technologies that exploit the effects of quantum mechanics. As part of this ongoing effort, devices for information processing, secure…

Quantum Physics · Physics 2015-04-02 G. Kurizki , P. Bertet , Y. Kubo , K. Mølmer , D. Petrosyan , P. Rabl , J. Schmiedmayer

We have studied theoretically the basic operation of a quantum feedback loop designed to maintain the desired phase of quantum coherent oscillations in a two-level system. Such feedback can suppress the dephasing of oscillations due to…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Rusko Ruskov , Alexander N. Korotkov

Consider a joint quantum state of a system and its environment. A measurement on the environment induces a decomposition of the system state. Using algorithmic information theory, we define the preparation information of a pure or mixed…

Quantum Physics · Physics 2015-06-26 Andrei N. Soklakov , Ruediger Schack

Networks of quantum devices with coherent control over their configuration offer promising advantages in quantum information processing. So far, the investigation of these advantages assumed that the control system was initially…

Quantum Physics · Physics 2024-05-21 Tamal Guha , Saptarshi Roy , Giulio Chiribella

The purpose of this paper is to formalize the concept that best synthesizes our intuitive understanding of quantum mechanics -- that the information carried by a system is limited -- and, from this principle, to construct the foundations of…

Quantum Physics · Physics 2025-07-04 Paolo Ferro

It is commonly stated that decoherence in open quantum systems is due to growing entanglement with an environment. In practice, however, surprisingly often decoherence may equally well be described by random unitary dynamics without…

Quantum Physics · Physics 2009-10-29 Julius Helm , Walter T. Strunz

For a transition $F_e=0\leftrightarrow F_g=1$ driven by a linearly polarized light and probed by a circularly light, quantum coherence effects are investigated. Due to the coherence between the drive Rabi frequency and Zeeman splitting,…

Quantum Physics · Physics 2009-11-07 Ying Gu , Qingqing Sun , Qihuang Gong

In this letter we define a family of entanglement distribution protocols assisted by feedback classical communication that gives an operational interpretation to reverse coherent information, i.e., the symmetric counterpart of the well…

Quantum Physics · Physics 2015-05-13 Raúl García-Patrón , Stefano Pirandola , Seth Lloyd , Jeffrey H. Shapiro

We propose a multiple-range quantum communication channel to realize coherent two-way quantum state transport with high fidelity. In our scheme, an information carrier (a qubit) and its remote partner are both adiabatically coupled to the…

Quantum Physics · Physics 2016-10-11 B. Chen , Y. D. Peng , Y. Li , X. F. Qian

Quantum coherence is a fundamental property of quantum systems, separating quantum from classical physics. Recently, there has been significant interest in the characterization of quantum coherence as a resource, investigating how coherence…

If the information is encoded into the state of the subsystem $S$ of a quantum system initially (at $t=0$), then it becomes distributed over the whole quantum system at $t>0$ due to the quantum interactions. Consequently, this information,…

Quantum Physics · Physics 2015-05-30 A. I. Zenchuk

The response of an arbitrary closed quantum system to a partially coherent electric field is investigated, with a focus on the transient coherences in the system. As a model we examine, both perturbatively and numerically, the coherences…

Quantum Physics · Physics 2014-03-05 Z. S. Sadeq , Paul Brumer

We consider a quantum state shared between many distant locations, and define a quantum information processing primitive, state merging, that optimally merges the state into one location. As announced in [Horodecki, Oppenheim, Winter,…

Quantum Physics · Physics 2008-06-12 Michal Horodecki , Jonathan Oppenheim , Andreas Winter