Formation and Migration of Vacancies in SiC

Spin defects in diamond and silicon carbide (SiC) are promising platforms for quantum information science applications. SiC is a particularly attractive material because of its ease of growth and microfabrication compared to diamond, and its integrability into existing optoelectronic devices. Divacancy defects in SiC have been shown [1] to host optically active electronic spins with long coherence times even at room temperature, thus providing a basis for quantum technologies. However, the formation mechanism and migration properties of point defects in SiC are poorly understood and hence difficult to control. Using advanced simulation techniques, we gain insight into the creation, interaction and migration of vacancies in SiC, aimed at deriving rules for the design of robust defects in scalable quantum materials. In particular, we used a combination of enhanced sampling methods coupled with classical Molecular Dynamics, and Density Functional Theory to investigate the defect electronic properties. We compare our results with thermal annealing and photoluminescence experiments, and we discuss possible processing conditions for the formation of divacancy defects with favorable spin states.

[1] D. J. Christle, et al. “Isolated electron spins in silicon carbide with millisecond coherence times” Nat. Mater. 14, 160 (2015)