Tunable cavity coupling to spin defects in 4H-silicon-carbide-on-insulator platform

TL;DR

This paper demonstrates the integration of tunable micro-ring cavities with spin defects in 4H-SiC, achieving enhanced photon confinement and control, advancing the development of scalable quantum photonic circuits.

Contribution

It introduces a scalable platform for integrating tunable micro-ring cavities with spin defects in 4H-SiC nanophotonics, enabling enhanced quantum control.

Findings

Purcell factor increased by approximately 5.0 under resonance.

Twofold increase in ODMR contrast observed.

Coherent control of PL4 spins achieved in integrated cavities.

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. While micro-ring cavities have been extensively studied in SiC and other materials, the integration of 4H-SiC spin defects into these critical structures, along with continuous mode tunability, remains unexplored. In this work, we demonstrate the integration of PL4 divacancy spin defects into tunable micro-ring cavities in scalable thin-film 4H-SiC nanophotonics. Comparing on- and off-resonance conditions, we observed an enhancement of the Purcell factor by approximately 5.0. This enhancement effectively confined coherent photons within the coupled waveguide, leading to a twofold increase in the ODMR (optically detected magnetic resonance) contrast and coherent control of PL4 spins. These advancements lay the foundation for developing SiC-based quantum photonic circuits.