High Energy Physics Seminar: Dr. Matthew M Roberts, University of Chicago
Title: “Response theory of relativistic quantum Hall: A new topological current"
Abstract: Motivated by observations of the quantum Hall effect in graphene, we consider the effective field theory of relativistic quantum Hall states. We find that in addition to the well-known Chern-Simons term, the effective action contains a new term of topological nature which couples the electromagnetic field with a topologically conserved current of 2+1 dimensional relativistic fluid. Unlike the Chern-Simons term, this new current involves the spacetime metric in a nontrivial way.
We extract predictions of the effective theory for linear electromagnetic and stress responses. We will also discuss additional constraints that occur when working at the zeroth Landau level, constraints from imposing conformal invariance, as well as coupling of this new topological current to a superfluid.