Indistinguishable near infra-red single photons from an individual organic molecule

TL;DR

This paper demonstrates a near-infrared single-photon source from an organic molecule that produces highly indistinguishable photons, suitable for quantum information applications, with detailed analysis of temperature effects on photon coherence.

Contribution

It introduces a new single-photon source based on an organic molecule with near-ideal indistinguishability at low temperatures, advancing quantum photonics technology.

Findings

Achieved >50% two-photon coalescence probability at 2 K

Studied temperature-dependent dephasing effects on photon interference

Generated polarization-entangled photon pairs for quantum applications

Abstract

By using the zero-phonon line emission of an individual organic molecule, we realized a source of indistinguishable single photons in the near infrared. A Hong-Ou-Mandel interference experiment is performed and a two-photon coalescence probability of higher than 50% at 2 K is obtained. The contribution of the temperature-dependent dephasing processes to the two-photon interference contrast is studied. We show that the molecule delivers nearly ideal indistinguishable single photons at the lowest temperatures when the dephasing is nearly lifetime limited. This source is used to generate post-selected polarization-entangled photon pairs, as a test-bench for applications in quantum information.