Experimental entanglement activation from discord in a programmable quantum measurement

Adesso, Gerardo and D'ambrosio, Vincenzo and Nagali, Eleonora and Piani, Marco and Sciarrino, Fabio (2014) Experimental entanglement activation from discord in a programmable quantum measurement. Physical Review Letters, 112 (14). 140501. ISSN 1079-7114 (https://doi.org/10.1103/PhysRevLett.112.140501)

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Abstract

In quantum mechanics, observing is not a passive act. Consider a system of two quantum particles A and B: if a measurement apparatus M is used to make an observation on B, the overall state of the system AB will typically be altered. When this happens, no matter which local measurement is performed, the two objects A and B are revealed to possess peculiar correlations known as quantum discord. Here, we demonstrate experimentally that the very act of local observation gives rise to an activation protocol which converts discord into distillable entanglement, a stronger and more useful form of quantum correlations, between the apparatus M and the composite system AB. We adopt a flexible two-photon setup to realize a three-qubit system (A, B, M) with programmable degrees of initial correlations, measurement interaction, and characterization processes. Our experiment demonstrates the fundamental mechanism underpinning the ubiquitous act of observing the quantum world and establishes the potential of discord in entanglement generation.

ORCID iDs

Adesso, Gerardo, D'ambrosio, Vincenzo, Nagali, Eleonora, Piani, Marco ORCID logoORCID: https://orcid.org/0000-0002-4698-9497 and Sciarrino, Fabio;
  • Item type:Article
    ID code:51628
    Dates:
    Date
    Event
    11 April 2014
    Published
    7 April 2014
    Published Online
    13 March 2014
    Accepted
    Notes:(c) American Physical Society
    Subjects:Science > Physics
    Department:Faculty of Science > Physics
    Depositing user: Pure Administrator
    Date deposited:12 Feb 2015 15:34
    Last modified:11 Nov 2024 10:56
    Related URLs:
    URI:https://strathprints.strath.ac.uk/id/eprint/51628
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