Abstract
18 years after the discovery of superconductivity in the perovskite Sr2RuO4, basic questions about the nature of the superconducting order parameter remain. Almost immediately after the discovery of superconductivity, it was realized theoretically that it might be a chiral p-wave state, the solid-state analogue of the A-phase of superfluid Helium 3. If so, it would be the only known example so far of this exotic time-reversal symmetry breaking state in electronic systems.
After more than a decade and a half of intense experimental effort, however, the question of whether Sr2RuO4 is chiral p-wave still lacks a definitive answer. In this talk, I will review some of these experiments as well as theory, highlighting signatures of time-reversal symmetry-breaking coming from Kerr rotation measurements as well as the seeming absence of topological time-reversal symmetry-breaking edge currents implied by SQUID microscopy experiments. I will argue that the multiband nature of Sr2RuO4 and its large spin-orbit coupling will likely play a central role in interpreting these experiments.
Coffee and tea will be served 20 minutes prior to the seminar.