Strain-induced modification of spin-optical dynamics in silicon vacancy centers for integrated quantum technologies

TL;DR

This study investigates how lattice strain affects the spin and optical properties of silicon vacancy centers in silicon carbide, crucial for their integration into quantum technologies, revealing strain's impact on transition rates and photon emission.

Contribution

It introduces a comprehensive optical pulse sequence and a strain Hamiltonian analysis to systematically characterize strain effects on VSi centers.

Findings

Strain reduces transition rates from metastable to ground states.

Strain decreases photon emission from VSi centers.

Axial and transverse strain contributions are quantitatively isolated.

Abstract

Silicon vacancy (VSi) centers in 4H silicon carbide have emerged as a highly promising platform for semiconductor-based quantum technologies, combining excellent spin and optical properties with an industrial-grade, CMOS-compatible material. As these defects are increasingly integrated into practical quantum devices, they inevitably encounter lattice strain. However, while the impact of strain is well documented for other solid-state defects like NV centers in diamond, its specific influence on key VSi spin dynamics such as initialization fidelity and state lifetimes remain largely unexplored. In this work, we address this critical gap by designing fully optical pulse sequences and incorporating the effective spin-3/2 strain Hamiltonian into our analysis. This combined approach allows us to isolate both axial and transverse strain contributions and systematically characterize their effect on the metastable state transition rates. Specifically, we reveal that strain significantly reduces the transition rates from the energetically lowest metastable state to the ground state quartet, leading to decreased photon emission. Supported by first-principles calculations, our findings provide a deeper understanding of VSi spin-strain dynamics, yielding crucial insights for the robust deployment of these centers in realistic, strain-prone environments.