Cavity-Enhanced Photon Emission from a Single Germanium-Vacancy Center in a Diamond Membrane

TL;DR

This paper demonstrates enhanced photon emission from a germanium-vacancy center in diamond using a high-finesse fiber cavity, promising improved quantum light sources with spectral stability for quantum information applications.

Contribution

It introduces a cavity-enhanced system with a germanium-vacancy center, showing significant emission enhancement over previous defect-based emitters.

Findings

31-fold increase in spectral density of emission

Coupling to a high-finesse fiber cavity

Potential for cryogenic emission rate enhancement

Abstract

The nitrogen-vacancy center in diamond has been explored extensively as a light-matter interface for quantum information applications, however it is limited by low coherent photon emission and spectral instability. Here, we present a promising interface based on an alternate defect with superior optical properties (the germanium-vacancy) coupled to a finesse $\approx11{,}000$ fiber cavity, resulting in a $31^{+11}_{-15}$-fold increase in the spectral density of emission. This work sets the stage for cryogenic experiments, where we predict a measurable increase in the spontaneous emission rate.