Temperature dependence of photoluminescence intensity and spin contrast in nitrogen-vacancy centers

TL;DR

This study investigates how temperature affects the photoluminescence and spin contrast of nitrogen-vacancy centers in diamond, revealing complex dependencies and developing a model to explain the underlying excited-state dynamics.

Contribution

The paper introduces a comprehensive model based on spin mixing and orbital hopping that explains temperature-dependent PL and spin contrast in NV centers.

Findings

PL intensity and spin contrast decrease between 10-100 K and recover outside this range

Dependence on magnetic bias field and crystal strain observed

Model accurately predicts temperature effects on NV center properties

Abstract

We report on measurements of the photoluminescence (PL) properties of single nitrogen-vacancy (NV) centers in diamond at temperatures between 4-300 K. We observe a strong reduction of the PL intensity and spin contrast between ca. 10-100 K that recovers to high levels below and above. Further, we find a rich dependence on magnetic bias field and crystal strain. We develop a comprehensive model based on spin mixing and orbital hopping in the electronic excited state that quantitatively explains the observations. Beyond a more complete understanding of the excited-state dynamics, our work provides a novel approach for probing electron-phonon interactions and a predictive tool for optimizing experimental conditions for quantum applications.