First-Principles Framework for the Prediction of Intersystem Crossing Rates in Spin Defects: The Role of Electron Correlation

TL;DR

This paper introduces a first-principles computational framework to accurately predict intersystem crossing rates in spin defects, crucial for quantum technology applications, by effectively modeling electron correlation, spin-orbit coupling, and electron-phonon interactions.

Contribution

It presents a novel first-principles method that captures electron correlation effects in spin defect dynamics, validated by experimental fluorescence lifetime measurements.

Findings

Accurately predicts intersystem crossing rates in NV centers

Demonstrates excellent agreement with experimental fluorescence lifetimes

Provides a versatile tool for exploring optical cycles of spin defects

Abstract

Optically active spin defects in solids are promising platforms for quantum technologies. Here, we present a first-principles framework to investigate intersystem crossing processes, which represent crucial steps in the optical spin-polarization cycle used to address spin defects. Considering the nitrogen-vacancy center in diamond as a case study, we demonstrate that our framework effectively captures electron correlation effects in the calculation of many-body electronic states and their spin-orbit coupling and electron-phonon interactions, while systematically addressing finite-size effects. We validate our predictions by carrying out measurements of fluorescence lifetimes, finding excellent agreement between theory and experiments. The framework presented here provides a versatile and robust tool for exploring the optical cycle of varied spin defects entirely from first principles.