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arXiv · 1804.01334

Witnessing genuine multi-photon indistinguishability

Daniel J. Brod·Ernesto F. Galvão·Niko Viggianiello·Fulvio Flamini·Nicolò Spagnolo·Fabio Sciarrino
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Abstract

Bosonic interference is a fundamental physical phenomenon, and it is believed to lie at the heart of quantum computational advantage. It is thus necessary to develop practical tools to witness its presence, both for a reliable assessment of a quantum source and for fundamental investigations. Here we describe how linear interferometers can be used to unambiguously witness genuine n-boson indistinguishability. The amount of violation of the proposed witnesses bounds the degree of multi-boson indistinguishability, for which we also provide a novel intuitive model using set theory. We experimentally implement this test to bound the degree of 3-photon indistinguishability in states we prepare using parametric down-conversion. Our approach results in a convenient tool for practical photonic applications, and may inspire further fundamental advances based on the operational framework we adopt.

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Daniel J. Brod, Ernesto F. Galvão, Niko Viggianiello, Fulvio Flamini, Nicolò Spagnolo, Fabio Sciarrino. 2018-04-04. Witnessing genuine multi-photon indistinguishability. https://doi.org/10.1103/physrevlett.122.063602

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