E-Mail Alert

Add your e-mail address to receive forthcoming issues of this journal:

Journal Browser

Journal Browser

Special Issue "Quantum Information"

Quicklinks

A special issue of Entropy (ISSN 1099-4300). This special issue belongs to the section "Quantum Information".

Deadline for manuscript submissions: closed (30 April 2010)

Special Issue Editor

Guest Editor
Dr. Peter Harremoës (Website)

Copenhagen Business College, Rønne Alle 1, st., DK-2860 Søborg, Denmark
Interests: symmetry; information divergence; cause and effect; Maxwell\'s demon; probability and statistics

Keywords

  • von Neumann entropy
  • Renyi entropies
  • channel capacities
  • additivity
  • de Finetti theorem
  • quantum cryptography

Published Papers (4 papers)

View options order results:
result details:
Displaying articles 1-4
Export citation of selected articles as:

Research

Jump to: Review

Open AccessArticle Roofs and Convexity
Entropy 2010, 12(7), 1799-1832; doi:10.3390/e12071799
Received: 5 June 2010 / Revised: 5 July 2010 / Accepted: 9 July 2010 / Published: 20 July 2010
Cited by 19 | PDF Full-text (394 KB) | HTML Full-text | XML Full-text
Abstract
Convex roof extensions are widely used to create entanglement measures in quantum information theory. The aim of the article is to present some tools which could be helpful for their treatment. Sections 2 and 3 introduce into the subject. It follows descriptions [...] Read more.
Convex roof extensions are widely used to create entanglement measures in quantum information theory. The aim of the article is to present some tools which could be helpful for their treatment. Sections 2 and 3 introduce into the subject. It follows descriptions of the Wootters' method, of the "subtraction procedure", and examples on how to use symmetries. Full article
(This article belongs to the Special Issue Quantum Information)
Open AccessArticle Measurement Back-Action in Quantum Point-Contact Charge Sensing
Entropy 2010, 12(7), 1721-1732; doi:10.3390/e12071721
Received: 10 May 2010 / Revised: 21 June 2010 / Accepted: 25 June 2010 / Published: 29 June 2010
Cited by 3 | PDF Full-text (1597 KB) | HTML Full-text | XML Full-text
Abstract
Charge sensing with quantum point-contacts (QPCs) is a technique widely used in semiconductor quantum-dot research. Understanding the physics of this measurement process, as well as finding ways of suppressing unwanted measurement back-action, are therefore both desirable. In this article, we present experimental [...] Read more.
Charge sensing with quantum point-contacts (QPCs) is a technique widely used in semiconductor quantum-dot research. Understanding the physics of this measurement process, as well as finding ways of suppressing unwanted measurement back-action, are therefore both desirable. In this article, we present experimental studies targeting these two goals. Firstly, we measure the effect of a QPC on electron tunneling between two InAs quantum dots, and show that a model based on the QPC’s shot-noise can account for it. Secondly, we discuss the possibility of lowering the measurement current (and thus the back-action) used for charge sensing by correlating the signals of two independent measurement channels. The performance of this method is tested in a typical experimental setup. Full article
(This article belongs to the Special Issue Quantum Information)
Open AccessArticle Eigenvalue and Entropy Statistics for Products of Conjugate Random Quantum Channels
Entropy 2010, 12(6), 1612-1631; doi:10.3390/e12061612
Received: 4 May 2010 / Revised: 17 June 2010 / Accepted: 18 June 2010 / Published: 23 June 2010
Cited by 7 | PDF Full-text (676 KB) | HTML Full-text | XML Full-text
Abstract
Using the graphical calculus and integration techniques introduced by the authors, we study the statistical properties of outputs of products of random quantum channels for entangled inputs. In particular, we revisit and generalize models of relevance for the recent counterexamples to the [...] Read more.
Using the graphical calculus and integration techniques introduced by the authors, we study the statistical properties of outputs of products of random quantum channels for entangled inputs. In particular, we revisit and generalize models of relevance for the recent counterexamples to the minimum output entropy additivity problems. Our main result is a classification of regimes for which the von Neumann entropy is lower on average than the elementary bounds that can be obtained with linear algebra techniques. Full article
(This article belongs to the Special Issue Quantum Information)
Figures

Review

Jump to: Research

Open AccessReview Using Quantum Computers for Quantum Simulation
Entropy 2010, 12(11), 2268-2307; doi:10.3390/e12112268
Received: 2 October 2010 / Revised: 2 November 2010 / Accepted: 10 November 2010 / Published: 15 November 2010
Cited by 30 | PDF Full-text (226 KB)
Abstract
Numerical simulation of quantum systems is crucial to further our understanding of natural phenomena. Many systems of key interest and importance, in areas such as superconducting materials and quantum chemistry, are thought to be described by models which we cannot solve with [...] Read more.
Numerical simulation of quantum systems is crucial to further our understanding of natural phenomena. Many systems of key interest and importance, in areas such as superconducting materials and quantum chemistry, are thought to be described by models which we cannot solve with sufficient accuracy, neither analytically nor numerically with classical computers. Using a quantum computer to simulate such quantum systems has been viewed as a key application of quantum computation from the very beginning of the field in the 1980s. Moreover, useful results beyond the reach of classical computation are expected to be accessible with fewer than a hundred qubits, making quantum simulation potentially one of the earliest practical applications of quantum computers. In this paper we survey the theoretical and experimental development of quantum simulation using quantum computers, from the first ideas to the intense research efforts currently underway. Full article
(This article belongs to the Special Issue Quantum Information)
Figures

Journal Contact

MDPI AG
Entropy Editorial Office
St. Alban-Anlage 66, 4052 Basel, Switzerland
entropy@mdpi.com
Tel. +41 61 683 77 34
Fax: +41 61 302 89 18
Editorial Board
Contact Details Submit to Entropy
Back to Top