Enhancement of silicon vacancy fluorescence intensity in silicon carbide using a dielectric cavity

Over the past decades, spin qubits in silicon carbide (SiC) have emerged as promising platforms for a wide range of quantum technologies. The fluorescence intensity holds significant importance in the performance of quantum photonics, quantum information process, and sensitivity of quantum sensing. In this work, a dual-layer Au/SiO₂ dielectric cavity is employed to enhance the fluorescence intensity of a shallow silicon vacancy ensemble in 4H-SiC. Experimental results demonstrate an effective fourfold augmentation in fluorescence counts at saturating laser power, corroborating our theoretical predictions. Based on this, we further investigate the influence of dielectric cavities on the contrast and linewidth of optically detected magnetic resonance (ODMR). There is a 1.6-fold improvement in magnetic field sensitivity. In spin echo experiments, coherence times remain constant regardless of the thickness of dielectric cavities. These experiments pave the way for broader applications of dielectric cavities in SiC-based quantum technologies.