KIAS workshop "From correlated electrons to nanoscale materials"

at Korea Institute for Advanced Study (KIAS), Seoul, Korea

• Joel Moore
  
  University of California, Berkeley
  
  

  Title

  Topological insulators in two and three dimensions

  Abstract

  Topological insulators are nonmagnetic band insulators in which spin- orbit coupling acts in roughly similar fashion to the magnetic field in the integer quantum Hall effect. These materials are insulating except at boundaries, where there are protected edge or surface states that may have been detected in recent experiments on heavy semiconductors at Wuerzburg and Princeton. While the two-dimensional topological insulator is closely connected to the integer quantum Hall effect, the strong topological insulator in three dimensions is more subtle and has several novel properties, including a protected surface state with Dirac-like excitations as in graphene. Other interesting properties in the three-dimensional case, realized in BiSb, include an unusual proximity effect (when the system is next to a superconductor) and a magnetoelectric effect of topological origin. This talk reviews the theoretical understanding of these states, discusses recent experimental progress, and (as time permits) presents some new work on a three-dimensional topological insulator state in correlated electron materials.