Dynamic stabilization of the optical resonances of single nitrogen-vacancy centers in diamond

TL;DR

This paper demonstrates electrical tuning and dynamic stabilization of the optical resonances of single nitrogen-vacancy centers in diamond, significantly reducing spectral drift and enhancing quantum communication applications.

Contribution

It introduces a method for electrical Stark tuning and real-time feedback stabilization of NV center emission frequencies.

Findings

Achieved 300 GHz tuning range of ZPL emission.

Reduced spectral drift to below 16 MHz.

Demonstrated stable resonance locking over several minutes.

Abstract

We report electrical tuning by the Stark effect of the excited-state structure of single nitrogen-vacancy (NV) centers located less than ~100 nm from the diamond surface. The zero-phonon line (ZPL) emission frequency is controllably varied over a range of 300 GHz. Using high-resolution emission spectroscopy, we observe electrical tuning of the strengths of both cycling and spin-altering transitions. Under resonant excitation, we apply dynamic feedback to stabilize the ZPL frequency. The transition is locked over several minutes and drifts of the peak position on timescales greater than ~100 ms are reduced to a fraction of the single-scan linewidth, with standard deviation as low as 16 MHz (obtained for an NV in bulk, ultra-pure diamond). These techniques should improve the entanglement success probability in quantum communications protocols.