Single Color Center Spin Coherence revealed in Optically Detected Magnetic Resonance of an Ensemble of Silicon Vacancies in SiC

TL;DR

This paper develops a quantitative theory for optically detected magnetic resonance (ODMR) of silicon vacancy centers in SiC, enabling extraction of spin parameters and coherence times from experimental spectra.

Contribution

It introduces a steady-state Lindblad equation-based model to analyze ODMR spectra, allowing detailed characterization of spin properties and coherence times in silicon vacancy centers.

Findings

Measured $T_2$ coherence times are accessible via ODMR.

Predicted spectral line narrowing in isotopically purified SiC.

Extracted spin Hamiltonian parameters consistent with literature.

Abstract

We present a quantitative theory for simulating optically detected magnetic resonance (ODMR) measurements of optically-active spin centers using steady-state Lindblad equations. We apply the theory to an experimental ODMR spectrum associated with the negatively-charged silicon vacancy V2 center in 6H-SiC, showing that spin Hamiltonian parameters, optical transition rates, and even coherence times may be extracted, with values consistent with recent literature. Notably the $T_2$ spin coherence time is measurable, not just the $T_2^*$ dephasing time. Furthermore, we simulate the ODMR spectra of a V2 center in isotopically-purified 6H-SiC, and predict an order-of-magnitude narrowing of some, but not all spectral lines compared with natural abundance samples.