Progress toward cryogen-free spin-photon interfaces based on nitrogen-vacancy centers and optomechanics

Abstract

The implementation of quantum networks involving quantum memories and photonic channels without the need for cryogenics would be a major technological breakthrough. Nitrogen-vacancy centers have excellent spin properties even at room temperature, but phonon-induced broadening makes it challenging to coherently interface these spins with photons at noncryogenic temperatures. Inspired by recent progress in achieving high mechanical quality factors, we propose that this challenge can be overcome using spin-optomechanical transduction. We quantify the coherence of the interface by calculating the indistinguishability and single-photon purity of photons emitted from such a device and describe promising paths towards experimental implementation. Our results show that for ultrahigh mechanical quality factor frequency products, as have recently been achieved, our proposed interface could generate single photons with high indistinguishability and efficiency without cryogenic cooling, an important step towards room-temperature quantum networks.