Event Detail Information
Physics Colloquium: "Interaction effects on topological insulators and superconductors"
In recent years, we have seen remarkable progress in our ability to classify and characterize phases of quantum matter. This progress has been driven in part by the theoretical prediction and experimental realization of topological insulators: unusual materials, whose bulk is gapped and insulating, while the surface is gapless and conducting.
In this talk, I will describe how the original non-interacting picture of topological insulators (and related phases of matter) based on electronic band-structure is modified in the presence of strong interactions. As I will show, electronic correlations give rise to a host of qualitatively new phenomena such as: i) appearance of novel phases, absent in the non-interacting realm; ii) collapse of several phases in the non-interacting classification to a single phase; iii) in the case of 3d systems, existence of exotic gapped surface phases, akin to fractional quantum Hall fluids, whose excitations possess fractional electric charge and fractional statistics.