Quantum Discord Bounds the Amount of Distributed Entanglement

T. K. Chuan*, J. Maillard, K. Modi, T. Paterek, M. Paternostro, M. Piani

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

125 Citations (Scopus)

Abstract

The ability to distribute quantum entanglement is a prerequisite for many fundamental tests of quantum theory and numerous quantum information protocols. Two distant parties can increase the amount of entanglement between them by means of quantum communication encoded in a carrier that is sent from one party to the other. Intriguingly, entanglement can be increased even when the exchanged carrier is not entangled with the parties. However, in light of the defining property of entanglement stating that it cannot increase under classical communication, the carrier must be quantum. Here we show that, in general, the increase of relative entropy of entanglement between two remote parties is bounded by the amount of nonclassical correlations of the carrier with the parties as quantified by the relative entropy of discord. We study implications of this bound, provide new examples of entanglement distribution via unentangled states, and put further limits on this phenomenon.

Original languageEnglish
Article number070501
Number of pages5
JournalPhysical Review Letters
Volume109
Issue number7
DOIs
Publication statusPublished - 16 Aug 2012

Keywords

  • MIXED-STATE ENTANGLEMENT
  • ENTROPY

ASJC Scopus subject areas

  • Physics and Astronomy(all)

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