Single-photon radiation enhancement and far-field regulation based on twist angle defects lattice cavities

Efficient and versatile single-photon sources are crucial components for practical quantum communication. The weak coupling of micro-nano photonic structures with quantum dots significantly enhances single-photon performance by accelerating the photon radiation rate, regulating the far-field distribution, and enhancing photon collection efficiency. We propose a novel defect design, twist angle defects (TADs), which greatly improve far-field radiation patterns based on the band-folding principle. Through systematic optimization of the structural parameters, the TADs lattice cavity has achieved a collection efficiency approaching 90% and a Purcell factor exceeding 40. Furthermore, this cavity exhibits excellent robustness, with tolerances for positional shifts and hole radius variations being ±100 nm and ±5 nm, respectively. The TADs lattice cavity is fully compatible with existing micro-nano processing techniques, offering a promising new device for future quantum information experiments.