Entangling the Whole by Beam Splitting a Part

Croal C, Peuntinger C, Chille V, Marquardt C, Leuchs G, Korolkova N, Mista L (2015)

Publication Type: Journal article

Publication year: 2015

Journal

Physical Review Letters American Physical Society

Book Volume: 115

Article Number: 190501

Journal Issue: 19

DOI: 10.1103/PhysRevLett.115.190501

Abstract

A beam splitter is a basic linear optical element appearing in many optics experiments and is frequently used as a continuous-variable entangler transforming a pair of input modes from a separable Gaussian state into an entangled state. However, a beam splitter is a passive operation that can create entanglement from Gaussian states only under certain conditions. One such condition is that the input light is suitably squeezed. We demonstrate, experimentally, that a beam splitter can create entanglement even from modes which do not possess such a squeezing provided that they are correlated to, but not entangled with, a third mode. Specifically, we show that a beam splitter can create three-mode entanglement by acting on two modes of a three-mode fully separable Gaussian state without entangling the two modes themselves. This beam splitter property is a key mechanism behind the performance of the protocol for entanglement distribution by separable states. Moreover, the property also finds application in collaborative quantum dense coding in which decoding of transmitted information is assisted by interference with a mode of the collaborating party.

Authors with CRIS profile

Christoph Marquardt Lehrstuhl für Experimentalphysik (Optik) Gerhard Leuchs

Involved external institutions

University of St Andrews GB United Kingdom (GB) Max-Planck-Institut für die Physik des Lichts (MPL) / Max Planck Institute for the Science of Light DE Germany (DE) Palacky University Olomouc / Univerzita Palackého v Olomouci CZ Czech Republic (CZ)

How to cite

APA:

Croal, C., Peuntinger, C., Chille, V., Marquardt, C., Leuchs, G., Korolkova, N., & Mista, L. (2015). Entangling the Whole by Beam Splitting a Part. Physical Review Letters, 115(19). https://doi.org/10.1103/PhysRevLett.115.190501

MLA:

Croal, Callum, et al. "Entangling the Whole by Beam Splitting a Part." Physical Review Letters 115.19 (2015).

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