Entanglement generation and manipulation in the Hong-Ou-Mandel experiment: A hidden scenario beyond two-photon interference

TL;DR

This paper reveals a hidden entanglement generation mechanism in the Hong-Ou-Mandel experiment, where entanglement arises from single-photon detection and phase control, beyond traditional two-photon interference.

Contribution

It introduces a novel entanglement generation scenario in HOM experiments based on phase manipulation of entangled states, not just two-photon interference.

Findings

Entanglement can be generated between ions via single-photon detection.

The phase of the entangled state influences photon paths.

Simulation shows robustness against experimental errors.

Abstract

Hong-Ou-Mandel (HOM) effect was long believed to be a two-photon interference phenomenon. It describes the fact that two indistinguishable photons mixed at a beam splitter will bunch together to one of the two output modes. Considering the two single-photon emitters such as trapped ions, we explore a hidden scenario of the HOM effect, where entanglement can be generated between the two ions when a single photon is detected by one of the detectors. A second photon emitted by the entangled photon sources will be subsequently detected by the same detector. However, we can also control the fate of the second photon by manipulating the entangled state. Instead of two-photon interference, phase of the entangled state is responsible for photon's path in our proposal. Toward a feasible experimental realization, we conduct a quantum jump simulation on the system to show its robustness against experimental errors.