Cavity QED with Diamond Nanocrystals and Silica Microspheres

TL;DR

This paper demonstrates strong coupling in a cavity QED system using diamond nanocrystals with nitrogen vacancy centers coupled to silica microsphere whispering gallery modes, highlighting potential for quantum information applications.

Contribution

It reports the first observation of normal mode splitting in a hybrid nanocrystal-microsphere cavity QED system, combining NV centers with high-Q silica microspheres.

Findings

Normal mode splitting observed, indicating strong coupling.

Hybrid system leverages NV centers' spin properties and microsphere's high Q.

Potential for quantum information processing applications.

Abstract

Normal mode splitting is observed in a cavity QED system, in which nitrogen vacancy centers in diamond nanocrystals are coupled to whispering gallery modes in a silica microsphere. The composite nanocrystal-microsphere system takes advantage of the exceptional spin properties of nitrogen vacancy centers as well as the ultra high quality factor of silica microspheres. The observation of the normal mode splitting indicates that the dipole optical interaction between the relevant nitrogen vacancy center and whispering gallery mode has reached the strong coupling regime of cavity QED.