Ultrafast spectral diffusion measurement on nitrogen vacancy centers in nanodiamonds using correlation interferometry

TL;DR

This paper introduces a novel photon correlation interferometry method to measure rapid spectral diffusion in nitrogen vacancy centers in nanodiamonds, revealing dependencies on excitation conditions and suggesting ways to enhance photon indistinguishability.

Contribution

The study presents a new high-resolution technique for analyzing spectral diffusion in NV centers, surpassing previous methods in temporal resolution by six orders of magnitude.

Findings

Spectral diffusion rate depends on excitation power, temperature, and wavelength.

The method works despite spectral diffusion rates being much higher than photon detection rates.

Results suggest strategies to improve indistinguishable photon emission from nanodiamonds.

Abstract

Spectral diffusion is the phenomenon of random jumps in the emission wavelength of narrow lines. This phenomenon is a major hurdle for applications of solid state quantum emitters like quantum dots, molecules or diamond defect centers in an integrated quantum optical technology. Here, we provide further insight into the underlying processes of spectral diffusion of the zero phonon line of single nitrogen vacancy centers in nanodiamonds by using a novel method based on photon correlation interferometry. The method works although the spectral diffusion rate is several orders of magnitude higher than the photon detection rate and thereby improves the time resolution of previous experiments with nanodiamonds by six orders of magnitude. We study the dependency of the spectral diffusion rate on the excitation power, temperature, and excitation wavelength under off-resonant excitation. Our results suggest a strategy to increase the number of spectrally indistinguishable photons emitted by diamond nanocrystals.