Topologically protected spatial-phase mismatching for cavity-enhanced quantum memories

Microphotonic quantum memory presents a promising avenue for miniaturizing and scaling up memories for quantum network applications. While conventional microphotonic cavities can provide enhanced light-matter-interaction to improve the memory efficiency, they are constrained by inherent limitations when utilizing the quantum memory protocol of the revival of silenced echo (ROSE). These limitations primarily arise from the high sensitivity to cavity fabrication imperfections, which scatter stored optical modes into alternate modes and cause a subsequent reduction in efficiency. In this study, we propose that the incorporation of robust edge states and defect states in topological photonic crystals offers a solution to overcome this inherent limitation. The spatial-phase-mismatching effect that underlies ROSE is topologically protected, effectively mitigating the distortion of stored optical states caused by imperfection scattering and improves the memory efficiency.