Title: Electromagnetic Properties of Topological Superconductors Abstract:
Bulk topological superconductors (TSCs) are highly sought as potential platforms for topological quantum computation. Just as interesting, the gapless surface Majorana fluid expected to form at the boundary of a bulk TSC is predicted to exhibit a range of remarkable properties, such as a precisely quantized longitudinal thermal conductivity. One particularly interesting facet of this fluid concerns its response to electromagnetic probes. Since energy is the only conserved quantity carried by the Majorana fermions, the surface fluid couples gravitationally (via its energy-momentum tensor) to the electric and in-plane magnetic fields. In this talk, I will discuss electromagnetic probes of TSCs that couple both surface and bulk degrees of freedom. In particular, we predict novel power-law temperature-dependence of the Meissner effect in fully gapped TSCs, due to the gapless surface. We also predict a topological anomalous skin effect in Weyl TSCs. This should manifest as an optical absorption peak near 2 \Delta (twice the pairing energy) due transitions between bulk and chiral surface Majorana states. The latter may be relevant to the candidate Weyl TSC UTe2. Finally, if there is time I will discuss a novel quantum-critical "stacking" phenomenon predicted to occur on the surface of strong TSCs, due to charged impurities (which induce "quenched gravitational disorder" for the surface Majorana fluid).