Two-cavity-mediated photon-pair emission by one atom

TL;DR

This paper presents a novel on-demand photon-pair source using a single atom coupled to two optical fiber cavities, achieving high efficiency and enabling new quantum optics experiments.

Contribution

It introduces a new atom-cavity system for efficient photon-pair generation with direct emission from the ground state, advancing quantum light source technology.

Findings

Photon pairs generated with 16% efficiency into fibers

Theoretical simulation of strong coupling regime showing direct ground state emission

Proposal for experimental observation of double-vacuum-stimulated emission

Abstract

Photon-pair sources are widely used in quantum optics and quantum information experiments. Despite their broad deployment, there has not yet been an on-demand implementation with efficient into-fiber photon generation and high single-photon purity. Here we report on such a source based on a single atom with three energy levels in ladder configuration and coupled to two optical fiber cavities. We efficiently generate photon pairs with in-fiber emission efficiency of $\eta_{\mathrm{pair}}=16(1)\%$ and study their temporal correlation properties. We simulate theoretically a regime with strong atom-cavity coupling and find that photons are directly emitted from the ground state, i.e. without atomic population in any intermediate state. We propose a scenario to observe such a double-vacuum-stimulated effect experimentally.