First-principles investigation of spin defects in silicon-silicon carbide heterostructures

Silicon and silicon carbide (SiC) are promising material platforms for quantum information applications. One of their many advantages is the availability of advanced fabrication and manufacturing techniques. Nanophotonic silicon structures, for example, offer optical manipulation and integration capabilities, expanding the potential for on-chip quantum systems. Here we investigate the properties of spin defects in SiC nanostructures embedded in a silicon matrix, using first principles (FP) calculations based on density functional theory. We carry out calculations both at zero and finite temperature, and we perform FP molecular dynamics with the Qbox code. We focus on the divacancy in SiC and we investigate the impact of the interface between Si and SiC on its electronic structure and photoluminescence properties, with the goal of assessing its potential as an optically active qubit within embedded silicon carbide nanostructures.