2023/11/20 by Xing-Xiang Wang, Wang, Xing-Xiang, Tomohiro Amemiya +3
Physics and Astronomy · #FOS: Physical sciences #Mechanical and Optical Resonators #Mesoscale and Nanoscale Physics (cond-mat.mes-hall) #Optics (physics.optics) #Quantum optics and atomic interactions #Topological Materials and Phenomena
paper · pdf · doi:10.48550/arxiv.2311.11556
openalex publication_date 2023/11/20 · openalex created_date 2023/11/23 · openalex updated_date 2026/07/28
We investigate interference between topological interfacial modes in a semiconductor photonic crystal platform with Dirac frequency dispersions, which can be exploited for interferometry switch. It is showcased that, in a two-in/two-out structure with four topological waveguides, geometric phases of the two-component spinor wavefunctions of topological photonic modes accumulate at turning points of waveguides, which govern the interferences and split the electromagnetic energy into two output ports with relative power ratio tunable by the relative phase of inputs. We unveil that this brand-new photonic phenomenon is intimately related to the spin-momentum locking property of quantum spin Hall effect, and results from the symphonic contributions of three phase variables: the spinor phase and geometric phase upon design, and the global phase controlled from outside. The present findings open the door for manipulating topological interfacial modes, thus exposing a new facet of topological physics. The topology-driven interference can be incorporated into other devices which is expected to leave far-reaching impacts to advanced photonics, optomechanics and phononics applications.