Quantum Properties of Dichroic Silicon Vacancies in Silicon Carbide

Semiconductor defects allowing efficient interaction between spins and photons can serve as building blocks for scalable quantum networks. The silicon vacancy (VSi) in SiC possesses controllable, long-lived ground-state spins, for adjustable fluorescence properties. However, its broad distribution of emitted-photon energies at room temperature means VSi's feasibility needs to be checked at liquid-helium temperature, where phonon coupling is suppressed. This study finds a long spin-coherence time, a doubling in fluorescence intensity by spin control, and 40% photon emission into the zero-phonon line, indicating that VSi in SiC truly is promising for spin-based quantum technology.