Unidirectional disorder-immune transmission and reconfigurable route of Fermi arcs in photonic topological Weyl metamaterials

In this paper, we demonstrate the existence of multiple photonic Fermi arcs with the same transmission direction at the interface between two different topological Weyl media. The surface waves are not affected by the type and number of defects and can bypass defects for robust one-way transportation, which confirms the disorder-immune property of Fermi arcs. The reconfigurable routing of Fermi arc surface waves can be well realized by changing the gyromagnetic and chiral parameters of Weyl metamaterials in H-shaped channels. Moreover, the unidirectional excitation and controllable transmission of Fermi arcs can be realized by adopting the different signs of the propagation constant and different interface configurations in T-shaped channels. Our paper provides an insight into the topological properties of Fermi arcs between two topological Weyl systems.