Home Contact Links Jobs
Introduction Admissions Programs People Research Community Outreach News & Seminars
Photonic Topological Phases in Dispersive Metamaterials
Speaker Prof. Ruey-Lin Chern, National Taiwan University
Date 25 January 2018 (Thursday)
Time 14:30 - 16:00
Venue Room 4502 (Lift 25-26), HKUST

We analyze the photonic topological phases in dispersive metamaterials which satisfy the degenerate condition at a reference frequency, where the hybrid modes are decoupled and determined by two subsystems with degenerate eigenvalues. By introducing the pseudospin states as the eigenfield basis, the Hamiltonians of the hybrid modes represent the pesudospin-orbit interaction with spin 1, which result in nonzero spin Chern numbers that characterize the topological phases. In particular, the two hybrid modes comply with a fermionic-like pseudo time-reversal symmetry that ensures the Kramers degeneracy, leading to the topological protection of the helical edge states. The surface waves at the interface between a dielectric and the metamaterial, which correspond to the transition between a trivial and a topological phase, are analytically formulated in terms of the eigenfields. The topological characters of the helical edge states are further illustrated with the excitation of surface waves at an irregular boundary.