Role of indistinguishability and entanglement in Hong-Ou-Mandel interference and finite bandwidth effects of frequency entangled photons

TL;DR

This paper explores how indistinguishability and entanglement influence Hong-Ou-Mandel interference, especially considering finite bandwidth effects, by analyzing detection statistics and spectral indistinguishability in frequency-entangled photons.

Contribution

It introduces a new term in the coincidence detection probability related to spectral indistinguishability, treating all photonic degrees of freedom equally.

Findings

Identifies a new term in detection probability linked to spectral indistinguishability.

Shows the importance of finite bandwidth effects in HOM interference.

Relates quantum principles to entanglement monogamy.

Abstract

We investigate the relation between indistinguishability and quantum entanglement in Hong- Ou-Mandel-interference experiments theoretically and relate these quantum mechanical principles to the theorem of entanglement monogamy. Employing Glaubers theory of quantum coherence we compute the detection statistics in HOM-interference of frequency entangled photons, and find a new additional term in the coincidence detection probability, which is related to the spectral indistinguishability of the considered photons that arises from finite bandwidth effects, and therefore is relevant in the limit of low frequency separations or large single-photon bandwidths. Compared to previous work in that context we treat all photonic degrees of freedom (DOF) on equal footing.