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Updated: Jun 18, 2025

A Photonic System for Generating Unconditional Polarization-Entangled Photons Based on Multiple Quantum Interference
Published on: September 5, 2019
Purifying Photon Indistinguishability through Quantum Interference
Carlos F D Faurby1, Lorenzo Carosini2,3, Huan Cao2,3
1Center for Hybrid Quantum Networks (Hy-Q), Niels Bohr Institute, <a href="https://ror.org/035b05819">University of Copenhagen</a>, Blegdamsvej 17, Copenhagen 2100, Denmark.
Abstract:
Indistinguishability between photons is a key requirement for scalable photonic quantum technologies. We experimentally demonstrate that partly distinguishable single photons can be purified to reach near-unity indistinguishability by the process of quantum interference with ancillary photons followed by heralded detection of a subset of them. We report on the indistinguishability of the purified photons by interfering two purified photons and show improvements in the photon indistinguishability of 2.774(3)% in the low-noise regime, and as high as 10.2(5)% in the high-noise regime.
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