Level-crossing induced spin phenomena in SiC: a theoretical study

TL;DR

This paper presents a theoretical model for spin dynamics in defect centers in SiC, highlighting the role of level crossing phenomena in spin-dependent optical properties, with predictions aligning well with experimental data.

Contribution

A new theoretical approach explicitly modeling spin dynamics in defect centers, including multiple states and transitions, applied to silicon carbide's spin-3/2 centers.

Findings

Magnetic field influences photoluminescence and magnetic resonance spectra.

Level crossing phenomena significantly affect spin dynamics.

Theoretical results agree with experimental observations.

Abstract

A theoretical approach is proposed to treat the spin dynamics in defect color centers. The method explicitly takes into account the spin dynamics in the ground state and excited state of the defect center as well as spin state dependent transitions involving the ground state and excited state, as well as an additional intermediate state. The proposed theory is applied to treat spin-dependent phenomena is silicon carbide, namely, in spin-3/2 silicon-vacancy centers, VSi or V2 centers. Theoretical predictions of magnetic field dependent photoluminescence intensity and optically detected magnetic resonance spectra demonstrate an important role of level crossing phenomena in the spin dynamics of the ground state and excited state. The results are in good agreement with previously published experimental data [Phys. Rev. X, 6 (2016) 031014].