Quantifying n-photon indistinguishability with a cyclic integrated interferometer
- Resource Type
- Working Paper
- Authors
- Pont, Mathias; Albiero, Riccardo; Thomas, Sarah E.; Spagnolo, Nicolò; Ceccarelli, Francesco; Corrielli, Giacomo; Brieussel, Alexandre; Somaschi, Niccolo; Huet, Hêlio; Harouri, Abdelmounaim; Lemaître, Aristide; Sagnes, Isabelle; Belabas, Nadia; Sciarrino, Fabio; Osellame, Roberto; Senellart, Pascale; Crespi, Andrea
- Source
- Phys. Rev. X 12, 031033 (2022)
- Subject
- Quantum Physics
Physics - Optics
- Language
We report on a universal method to measure the genuine indistinguishability of n-photons - a crucial parameter that determines the accuracy of optical quantum computing. Our approach relies on a low-depth cyclic multiport interferometer with N = 2n modes, leading to a quantum interference fringe whose visibility is a direct measurement of the genuine n-photon indistinguishability. We experimentally demonstrate this technique for a 8-mode integrated interferometer fabricated using femtosecond laser micromachining and four photons from a quantum dot single-photon source. We measure a four-photon indistinguishability up to 0.81$\pm$0.03. This value decreases as we intentionally alter the photon pairwise indistinguishability. The low-depth and low-loss multiport interferometer design provides an efficient and scalable path to evaluate the genuine indistinguishability of resource states of increasing photon number.