Glide-Plane-Symmetric Waveguide for Spin Qubit Coupling

The patent applies asymmetry by introducing a glide-plane symmetry instead of mirror symmetry in the photonic-crystal waveguide structure. The nanostructures on opposite sides of the guiding region are shifted relative to each other along the propagation direction, creating an asymmetric configuration that generates in-plane circularly polarized modes. This asymmetric design enables efficient coupling with quantum emitters having circularly polarized transition dipole moments while maintaining fabrication feasibility through systematic structural modification.

The patent employs parameter changes by systematically varying the position and orientation of nanostructures to achieve glide-plane symmetry. Specifically, the nanostructures on opposite sides are shifted by a controlled amount along the propagation direction, and their orientations are adjusted accordingly. This parameter modification transforms the symmetric structure into one that supports in-plane circularly polarized modes, enabling efficient coupling with spin qubits while maintaining a relatively simple and systematic structural modification approach.