Topological transitions in magnetized plasma and optical isolators based on leaky waveguide plasmon mode

Topological transitions open a fundamentally new route of research with interesting optical phenomena in photonic metamaterials. In this work, we comprehensively investigate the topology of equifrequency surfaces in magnetized plasma. The full topological phase diagrams are shown and the critical points in the topological transitions are given. The equifrequency surfaces evolve from the closed-form ellipsoid to the open forms type-I or type-II hyperboloid in the topological transitions. Remarkably, a type of nonreciprocal optical isolator is demonstrated utilizing the transformation from topological surface states to leaky modes in magnetized plasma. Our work may provide additional insights into topological wave physics and the novel optical isolator has potential applications in light modulation.