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). pp. 140501-1. ISSN 1079-7114

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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.

Item Type: Article
Additional Information: ©2014 American Physical Society
Schools/Departments: University of Nottingham, UK > Faculty of Science > School of Mathematical Sciences
Identification Number: 10.1103/PhysRevLett.112.140501
Depositing User: Eprints, Support
Date Deposited: 12 Oct 2017 08:00
Last Modified: 14 Oct 2017 08:26
URI: http://eprints.nottingham.ac.uk/id/eprint/47219

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