Skip to main content
Top

Contractive freedoms of ensembles and quantum channels for infinite-dimensional systems

  • 01-08-2019
Published in:

Activate our intelligent search to find suitable subject content or patents.

search-config
loading …

Abstract

In this paper, we reveal that the unitary freedom in ensemble of pure states with a given state and the unitary freedom in operator-sum representation for a given channel are no longer valid for infinite-dimensional systems. The replacements of them are, respectively, the contractive freedom in ensemble and the contractive freedom in operator-sum representation. Precisely, we show that, (1) two ensembles \(\{|\phi _i\rangle , p_i\}\) and \(\{|\psi _j\rangle , q_j\}\) determine the same state if and only if there exists some contractive matrix \(V=(v_{ij})\) such that \(\sqrt{p_i}|\phi _i\rangle =\sum _j v_{ij}\sqrt{q_j}|\psi _j\rangle \) for each i; (2) two sequences \(\{A_i\}\) and \(\{B_j\}\) of Kraus operators in operator-sum representations determine the same quantum channel if and only if there exists some contractive matrix \(V=(v_{ij})\) such that \(A_i=\sum _jv_{ij}B_j\) for each i. All possible quantum ensembles of pure states with any given state and all possible operator-sum representations of any given channel are described.

Dont have a licence yet? Then find out more about our products and how to get one now:

Springer Professional "Business + Economics & Engineering + Technology"

Online-Abonnement

Springer Professional "Business + Economics & Engineering + Technology" gives you access to:

  • more than 130.000 books
  • more than 540 journals

from the following subject areas:

  • Automotive
  • Construction + Real Estate
  • Business IT + Informatics
  • Electrical Engineering + Electronics
  • Energy + Sustainability
  • Finance + Banking
  • Management + Leadership
  • Marketing + Sales
  • Mechanical Engineering + Materials
  • Surfaces + Materials Technology
  • Insurance + Risk


Secure your knowledge advantage now!

Springer Professional "Engineering + Technology"

Online-Abonnement

Springer Professional "Engineering + Technology" gives you access to:

  • more than 75.000 books
  • more than 390 journals

from the following specialised fileds:

  • Automotive
  • Business IT + Informatics
  • Construction + Real Estate
  • Electrical Engineering + Electronics
  • Energy + Sustainability
  • Mechanical Engineering + Materials
  • Surfaces + Materials Technology





 

Secure your knowledge advantage now!

Springer Professional "Business + Economics"

Online-Abonnement

Springer Professional "Business + Economics" gives you access to:

  • more than 100.000 books
  • more than 340 journals

from the following specialised fileds:

  • Construction + Real Estate
  • Business IT + Informatics
  • Finance + Banking
  • Management + Leadership
  • Marketing + Sales
  • Insurance + Risk



Secure your knowledge advantage now!

Title
Contractive freedoms of ensembles and quantum channels for infinite-dimensional systems
Authors
Zhoubo Duan
Jinchuan Hou
Publication date
01-08-2019
Publisher
Springer US
Published in
Quantum Information Processing / Issue 8/2019
Print ISSN: 1570-0755
Electronic ISSN: 1573-1332
DOI
https://doi.org/10.1007/s11128-019-2367-6
This content is only visible if you are logged in and have the appropriate permissions.
This content is only visible if you are logged in and have the appropriate permissions.