2020/10/04 by Charlie-Ray Mann, Mann, Charlie-Ray, Eros Mariani +1
Materials Science · Physics and Astronomy · #Atomic Physics (physics.atom-ph) #FOS: Physical sciences #Metamaterials and Metasurfaces Applications #Optics (physics.optics) #Quantum Mechanics and Non-Hermitian Physics #Quantum Physics (quant-ph) #Topological Materials and Phenomena
paper · pdf · doi:10.48550/arxiv.2010.01636
openalex publication_date 2020/10/04 · openalex created_date 2022/07/25 · openalex updated_date 2026/07/28
Topological phases of light exhibit unique properties beyond the realm of\nconventional photonics. In particular the valley-Hall topological insulator has\nbeen realized in a variety of photonic structures because it can be easily\ninduced by breaking certain lattice symmetries. However, the valley-Chern\nnumbers are usually fixed by design and the corresponding topological edge\nstates are forced to propagate in a fixed direction. Here, we propose a\nmechanism to induce topological transitions via accidental Dirac points in\nmetasurfaces composed of interacting dipole emitters/antennas. For a fixed\narrangement of dipoles, we show that the topological phase depends critically\non the surrounding electromagnetic environment which mediates the dipole-dipole\ninteractions. To access different topological phases we embed the metasurface\ninside a cavity waveguide where one can tune the dominant dipolar coupling from\nshort-range Coulomb interactions to long-range photon-mediated interactions by\nreducing the cavity width; this results in a topological transition\ncharacterized by an inversion of the valley-Chern numbers. Consequently, we\nshow that one can switch the chirality of the topological edge states by\nmodifying only the electromagnetic environment in which the dipoles are\nembedded. This mechanism could have important implications for other\ntopological phases such as photonic higher-order topological insulators.\n