Title: 4-Port Circulator Based on Bi-anisotropic Meta-Waveguide
As the E&M analog of the topological materials in condensed matter physics, recent studies of the photonics topological systems shed light on designing novel optical devices. In this talk, we present the experiments on the Bi-anisotropic Meta Waveguide system which is compatible with both Hall and spin-Hall topological insulating phases. With carefully engineered designs, combined photonic systems with multiple topological phases, like 4-port circulators, are proposed and experimentally tested. Spin degrees of freedom characterizing such topologically protected edgemodes determine their unique pathways through these systems, free from backscattering and able to travel around sharp corners.
Title: Josephson junctions with weak links of topological crystalline insulator nanowires
Incorporating superconductivity in topological states of matter offers potential routes to novel excitations with properties essential to topological quantum computation. Topological crystalline insulators (TCIs) are topological states of matter protected by crystalline symmetry rather than the more commonly used time-reversal invariant topological insulators. In this talk, we report on the fabrication of Josephson junctions using nanowires of SnTe, a TCI, as the weak link material. We show the divergence of our devices from standard Josephson junction behavior using DC techniques, highlighting intriguing novel behavior in the magnetic diffraction pattern, and discuss the origin of this behavior in terms of pi phase difference across the junction.