Deterministic and Scalable Coupling of Single 4H-SiC Spin Defects into Bullseye Cavities

TL;DR

This paper demonstrates the deterministic integration of single and ensemble spin defects in 4H-SiC bullseye cavities, achieving significant optical enhancement and coherent control, advancing scalable quantum photonic devices.

Contribution

It introduces a scalable method for coupling single and ensemble spin defects into monolithic bullseye cavities on 4H-SiC, enabling enhanced optical properties and coherent spin control.

Findings

40-fold enhancement of ZPL intensity for ensemble defects

Threefold increase in photon count rate for single defects

Successful demonstration of coherent spin control via ODMR and Rabi oscillations

Abstract

Silicon carbide (SiC) has attracted significant attention as a promising quantum material due to its ability to host long-lived, optically addressable color centers with solid-state photonic interfaces. The CMOS compatibility of 4H-SiCOI (silicon-carbide-on-insulator) makes it an ideal platform for integrated quantum photonic devices and circuits. However, the deterministic integration of single spin defects into high-performance photonic cavities on this platform has remained a key challenge. In this work, we demonstrate the deterministic and scalable coupling of both ensemble (PL4) and single PL6 spin defects into monolithic bullseye cavities on the 4H-SiCOI platform. By tuning the cavity resonance, we achieve a 40-fold enhancement of the zero-phonon line (ZPL) intensity from ensemble PL4 defects, corresponding to a Purcell factor of approximately 5.0. For deterministically coupled single PL6 defects, we observe a threefold increase in the saturated photon count rate, confirm single-photon emission, and demonstrate coherent control of the spin state through optically detected magnetic resonance (ODMR), resonant excitation, and Rabi oscillations. These advancements establish a viable pathway for developing scalable, high-performance SiC-based quantum photonic circuits.