Spin Coherence and Echo Modulation of the Silicon Vacancy in 4H-SiC at Room Temperature

TL;DR

This study investigates the spin coherence properties of silicon vacancies in 4H-SiC at room temperature, revealing field-dependent coherence times and echo modulation effects relevant for quantum technologies.

Contribution

It provides the first detailed measurement of spin echo decay and modulation of silicon vacancies in 4H-SiC at room temperature, with a theoretical explanation for the observed phenomena.

Findings

Spin echo decay time varies from <10 μs to 80 μs with magnetic field.

Strong field-dependent spin echo modulation observed.

Theoretical model explains interaction with nuclear spins.

Abstract

The silicon vacancy in silicon carbide is a strong emergent candidate for applications in quantum information processing and sensing. We perform room temperature optically-detected magnetic resonance and spin echo measurements on an ensemble of vacancies and find the properties depend strongly on magnetic field. The spin echo decay time varies from less than 10 $\mu$s at low fields to 80 $\mu$s at 68 mT, and a strong field-dependent spin echo modulation is also observed. The modulation is attributed to the interaction with nuclear spins and is well-described by a theoretical model.