Purcell Enhancement of a Single Silicon Carbide Color Center with Coherent Spin Control
Alexander L. Crook, Christopher P. Anderson, Kevin C. Miao, Alexandre Bourassa, Hope Lee, Sam L. Bayliss, David O. Bracher, Xingyu Zhang, Hiroshi Abe, Takeshi Ohshima, Evelyn L. Hu, D. D. Awschalom
Abstract
Silicon carbide has recently been developed as a platform for optically addressable spin defects. In particular, the neutral divacancy in the 4H polytype displays an optically addressable spin-1 ground state and near-infrared optical emission. Here, we present the Purcell enhancement of a single neutral divacancy coupled to a photonic crystal cavity. We utilize a combination of nanolithographic techniques and a dopant-selective photoelectrochemical etch to produce suspended cavities with quality factors exceeding 5000. Subsequent coupling to a single divacancy leads to a Purcell factor of ∼50, which manifests as increased photoluminescence into the zero-phonon line and a shortened excited-state lifetime. Additionally, we measure coherent control of the divacancy ground-state spin inside the cavity nanostructure and demonstrate extended coherence through dynamical decoupling. This spin-cavity system represents an advance toward scalable long-distance entanglement protocols using silicon carbide that require the interference of indistinguishable photons from spatially separated single qubits.