Get 20M+ Full-Text Papers For Less Than $1.50/day. Start a 14-Day Trial for You or Your Team.

Learn More →

Remedying the local ancilla problem with geometric discord

Remedying the local ancilla problem with geometric discord The geometric discord, as introduced by Dakić, Vedral, and Brukner ( Phys. Rev. Lett. PRLTAO 0031-9007 10.1103/PhysRevLett.105.190502 105 , 190502 ( 2010 ) ), is a significant figure of merit for quantum correlations with wide applications. However, it has a curious drawback in that it may change reversibly by trivially adding a local ancilla, as recently criticized by Piani ( Phys. Rev. A PLRAAN 1050-2947 10.1103/PhysRevA.86.034101 86 , 034101 ( 2012 ) ). This casts doubt on the information content and usage of geometric discord. In this work, we show that this problem with geometric discord can be remedied simply by starting from the square root of a density operator, rather than the density operator itself, in defining the discord. Moreover, most other basic properties and analytical aspects of the original geometric discord can be carried over to this modified discord. Due to the square-root character, which is reminiscent of probability amplitudes ubiquitous in quantum theory, the modified discord seems to capture quantum correlations in a more intrinsic and informational fashion. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Physical Review A American Physical Society (APS)

Remedying the local ancilla problem with geometric discord

Physical Review A , Volume 87 (6) – Jun 4, 2013
5 pages

Loading next page...
 
/lp/american-physical-society-aps/remedying-the-local-ancilla-problem-with-geometric-discord-xrJMmmeGsZ

References

References for this paper are not available at this time. We will be adding them shortly, thank you for your patience.

Publisher
American Physical Society (APS)
Copyright
©2013 American Physical Society
ISSN
1050-2947
DOI
10.1103/PhysRevA.87.062303
Publisher site
See Article on Publisher Site

Abstract

The geometric discord, as introduced by Dakić, Vedral, and Brukner ( Phys. Rev. Lett. PRLTAO 0031-9007 10.1103/PhysRevLett.105.190502 105 , 190502 ( 2010 ) ), is a significant figure of merit for quantum correlations with wide applications. However, it has a curious drawback in that it may change reversibly by trivially adding a local ancilla, as recently criticized by Piani ( Phys. Rev. A PLRAAN 1050-2947 10.1103/PhysRevA.86.034101 86 , 034101 ( 2012 ) ). This casts doubt on the information content and usage of geometric discord. In this work, we show that this problem with geometric discord can be remedied simply by starting from the square root of a density operator, rather than the density operator itself, in defining the discord. Moreover, most other basic properties and analytical aspects of the original geometric discord can be carried over to this modified discord. Due to the square-root character, which is reminiscent of probability amplitudes ubiquitous in quantum theory, the modified discord seems to capture quantum correlations in a more intrinsic and informational fashion.

Journal

Physical Review AAmerican Physical Society (APS)

Published: Jun 4, 2013

There are no references for this article.