Hierarchy of efficiently computable and faithful lower bounds to quantum discord

Marco Piani

Research output: Contribution to journalLetter

4 Citations (Scopus)

Abstract

Quantum discord expresses a fundamental non-classicality of correlations that is more general than entanglement, but that, in its standard definition, is not easily evaluated. We derive a hierarchy of computationally efficient lower bounds to the standard quantum discord. Every non-trivial element of the hierarchy constitutes by itself a valid discord-like measure, based on a fundamental feature of quantum correlations: their lack of shareability. Our approach emphasizes how the difference between entanglement and discord depends on whether shareability is intended as a static property or as a dynamical process.
LanguageEnglish
Article number080401
Number of pages6
JournalPhysical Review Letters
Volume117
Issue number8
DOIs
Publication statusPublished - 15 Aug 2016

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hierarchies

Keywords

  • quantum discord
  • quantum separability
  • quantum fidelity
  • hierarchy
  • quantum correlations
  • shareability
  • a semidefinite programming
  • entanglement

Cite this

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Hierarchy of efficiently computable and faithful lower bounds to quantum discord. / Piani, Marco.

In: Physical Review Letters, Vol. 117, No. 8, 080401, 15.08.2016.

Research output: Contribution to journalLetter

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AB - Quantum discord expresses a fundamental non-classicality of correlations that is more general than entanglement, but that, in its standard definition, is not easily evaluated. We derive a hierarchy of computationally efficient lower bounds to the standard quantum discord. Every non-trivial element of the hierarchy constitutes by itself a valid discord-like measure, based on a fundamental feature of quantum correlations: their lack of shareability. Our approach emphasizes how the difference between entanglement and discord depends on whether shareability is intended as a static property or as a dynamical process.

KW - quantum discord

KW - quantum separability

KW - quantum fidelity

KW - hierarchy

KW - quantum correlations

KW - shareability

KW - a semidefinite programming

KW - entanglement

UR - http://arxiv.org/abs/1501.06855

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