Cavity enhancement of V2 centers in 4H-SiC with a fiber-based Fabry–Perot microcavity

Silicon vacancy centers in 4H-silicon carbide (SiC) host a long-lived electronic spin with spin-resolved optical transitions. This makes them a great candidate for implementing a spin–photon interface, an important building block of quantum networks. However, the fraction of coherently scattered photons is intrinsically low, limiting the achievable communication rates. To address this problem, we integrate V2 centers within a SiC membrane into a fiber-based Fabry–Perot microcavity. We find that SiC is uniquely suited for this approach, offering extremely low losses as we evidence by a high cavity finesse F ≈40000 and naturally available maximal cavity–emitter coupling due to the perfect alignment of polarization modes and the dipole orientation. We observe a 13.3-fold Purcell enhancement of the zero phonon line of a single emitter, constituting an efficient source of coherent photons for this novel material platform, and opening the path toward a deterministic spin–photon interface.