Scalable Integration of Cavity-Enhanced Silicon Vacancy Centers on a CMOS-Compatible 4H-SiCOI Platform

Scalable solid-state quantum sensors require simultaneous advances in spin-readout fidelity, photon collection efficiency, and device-level integration, which so far have remained elusive on most material platforms. Here, we overcome these limitations by coupling silicon vacancy spin centers to an array of circular Bragg grating cavities on a scalable thin-film silicon carbide-on-insulator (4H-SiCOI) platform. By employing anti-Stokes excitation, we show that the cavity-enhanced emission compensates for intrinsically weak anti-Stokes absorption, yielding a 24.6-fold increase in collected fluorescence, a high 1.78% spin-readout contrast at zero field, and a 6.42-fold improvement in magnetometry sensitivity. This high spin-readout fidelity further enables the spectroscopic resolution of intrinsic dark-spin bath interactions in 4H-SiCOI, revealing the underlying decoherence mechanisms. Our work establishes cavity-enhanced anti-Stokes excitation as a general and feasible route for silicon carbide quantum technologies, paving the way for scalable manufacturing of spin-based quantum sensors and integrated photonic circuits.