Condensed Matter Seminar: "Topology of the Fermi Sea"
- Event Type
- Seminar/Symposium
- Sponsor
- Physics - Condensed Matter
- Location
- 190 ESB
- Date
- Apr 15, 2022 1:00 pm
- Speaker
- Charlie Kane, University of Pennsylvania
- Views
- 214
The Fermi sea in a metal is a topological object characterized by an integer topological invariant called the Euler characteristic, cF. In this talk we will argue that for a 2D fermi gas cF is reflected in a quantized frequency dependent non-linear 3 terminal conductance that generalizes the Landauer conductance in D=1. We will critically address the roles of electrical contacts and Fermi liquid interactions, and we will propose experiments on 2D Dirac materials, such as graphene, using a triple point contact geometry. We will go on to show that for a D dimensional Fermi gas, cF is also reflected in the multipartite entanglement characterizing D+1 regions that meet at a point. This generalizes a well-known result that relates the bipartite entanglement entropy of a 1+1D conformal field theory to its central charge c. We will argue that for an interacting 3D Fermi liquid, cF distinguishes distinct topological Fermi liquid phases.