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arXiv · 1907.01325

Experimental quantification of genuine four-photon indistinguishability

Taira Giordani·Daniel J. Brod·Chiara Esposito·Niko Viggianiello·Marco Romano·Fulvio Flamini·Gonzalo Carvacho·Nicolò Spagnolo·Ernesto F. Galvão·Fabio Sciarrino
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Abstract

Photon indistinguishability plays a fundamental role in information processing, with applications such as linear-optical quantum computation and metrology. It is then necessary to develop appropriate tools to quantify the amount of this resource in a multiparticle scenario. Here we report a four-photon experiment in a linear-optical interferometer designed to simultaneously estimate the degree of indistinguishability between three pairs of photons. The interferometer design dispenses with the need of heralding for parametric down-conversion sources, resulting in an efficient and reliable optical scheme. We then use a recently proposed theoretical framework to quantify genuine four-photon indistinguishability, as well as to obtain bounds on three unmeasured two-photon overlaps. Our findings are in high agreement with the theory, and represent a new resource-effective technique for the characterization of multiphoton interference.

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Taira Giordani, Daniel J. Brod, Chiara Esposito, Niko Viggianiello, Marco Romano, Fulvio Flamini, Gonzalo Carvacho, Nicolò Spagnolo, Ernesto F. Galvão, Fabio Sciarrino. 2019-07-02. Experimental quantification of genuine four-photon indistinguishability. https://doi.org/10.1088/1367-2630%2Fab7a30

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