Measurement-based method for verifying quantum discord

Rahimi-Keshari, Saleh, Caves, Carlton M. and Ralph, Timothy C. (2013) Measurement-based method for verifying quantum discord. Physical Review A, 87 1: 012119.1-012119.5. doi:10.1103/PhysRevA.87.012119

Attached Files (Some files may be inaccessible until you login with your UQ eSpace credentials)
Name Description MIMEType Size Downloads
UQ291540.pdf Full text (open access) application/pdf 99.64KB 0

Author Rahimi-Keshari, Saleh
Caves, Carlton M.
Ralph, Timothy C.
Title Measurement-based method for verifying quantum discord
Journal name Physical Review A   Check publisher's open access policy
ISSN 1050-2947
1094-1622
Publication date 2013-01-01
Year available 2013
Sub-type Article (original research)
DOI 10.1103/PhysRevA.87.012119
Open Access Status File (Publisher version)
Volume 87
Issue 1
Start page 012119.1
End page 012119.5
Total pages 5
Place of publication College Park, MD., United States
Publisher American Physical Society
Language eng
Subject 3107 Atomic and Molecular Physics, and Optics
Abstract We introduce a measurement-based method for verifying quantum discord of any bipartite quantum system. We show that by performing an informationally complete positive operator valued measurement (IC-POVM) on one subsystem and checking the commutativity of the conditional states of the other subsystem, quantum discord from the second subsystem to the first can be verified. This is an improvement upon previous methods, which enables us to efficiently apply our method to continuous-variable systems, as IC-POVM's are readily available from homodyne or heterodyne measurements. We show that quantum discord for Gaussian states can be verified by checking whether the peaks of the conditional Wigner functions corresponding to two different outcomes of heterodyne measurement coincide at the same point in the phase space. Using this method, we also prove that the only Gaussian states with zero discord are product states; hence, Gaussian states with Gaussian discord have nonzero quantum discord. DOI: 10.1103/PhysRevA.87.012119
Formatted abstract
We introduce a measurement-based method for verifying quantum discord of any bipartite quantum system. We show that by performing an informationally complete positive operator valued measurement (IC-POVM) on one subsystem and checking the commutativity of the conditional states of the other subsystem, quantum discord from the second subsystem to the first can be verified. This is an improvement upon previous methods, which enables us to efficiently apply our method to continuous-variable systems, as IC-POVM's are readily available from homodyne or heterodyne measurements. We show that quantum discord for Gaussian states can be verified by checking whether the peaks of the conditional Wigner functions corresponding to two different outcomes of heterodyne measurement coincide at the same point in the phase space. Using this method, we also prove that the only Gaussian states with zero discord are product states; hence, Gaussian states with Gaussian discord have nonzero quantum discord.
Keyword Continuous-Variable Systems
Information
Q-Index Code C1
Q-Index Status Confirmed Code
Grant ID CE11000102
PHY-1005540
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: School of Mathematics and Physics
Official 2014 Collection
 
Versions
Version Filter Type
Citation counts: TR Web of Science Citation Count  Cited 19 times in Thomson Reuters Web of Science Article | Citations
Scopus Citation Count Cited 20 times in Scopus Article | Citations
Google Scholar Search Google Scholar
Created: Sun, 17 Feb 2013, 10:22:45 EST by System User on behalf of School of Mathematics & Physics