Reconfigurable topological phases in next-nearest-neighbor coupled resonator lattices

• Main Authors: Leykam, Daniel, Mittal, S., Hafezi, M., Chong, Yi Dong
• Other Authors: School of Physical and Mathematical Sciences
• Format: Article
• Language: English
• Published: 2018
• Subjects: Lattices; Topological Photonic System; DRNTU::Science::Physics
• Online Access: https://hdl.handle.net/10356/88010; http://hdl.handle.net/10220/45606
• Institution: Nanyang Technological University

We present a reconfigurable topological photonic system consisting of a 2D lattice of coupled ring resonators, with two sublattices of site rings coupled by link rings, which can be accurately described by a tight-binding model. Unlike previous coupled-ring topological models, the design is translationally invariant, similar to the Haldane model, and the nontrivial topology is a result of next-nearest couplings with nonzero staggered phases. The system exhibits a topological phase transition between trivial and spin Chern insulator phases when the sublattices are frequency detuned. Such topological phase transitions can be easily induced by thermal or electro-optic modulators, or nonlinear cross phase modulation. We use this lattice to design reconfigurable topological waveguides, with potential applications in on-chip photon routing and switching.