Seminar M. Cubrovic

M. Cubrovic
Leiden University
AdS/CFT and strongly correlated electrons

We describe an AdS/CFT construction aimed at capturing the behavior of strongly interacting fermions in field theory. Holographic "dictionary entries" for quantities such as density or Fermi momentum are still elusive and one needs to tailor them for the problem at hand. We start from a phenomenological action, putting a charged black hole and a Dirac fermion in an AdS(4) background. Self-consistent calculation of the backreaction on the metric reveals that the true ground state is in fact a scaling Lifshitz-like geometry that can be understood as a black hole with Dirac hair. The bulk Dirac field behaves effectively as a single particle in the low-energy limit and its wavefunction now directly encodes the density, Fermi energy and other properties on the CFT side, which corresponds to a strongly interacting Fermi liquid. We thus gain a holographic argument for the (empirically well known) stability of the normal metallic state in condensed matter systems. If time permits, possible ways of destroying the Fermi liquid state will also be discussed, leading to AdS duals for Quantum Hall and superconducting systems.

Thursday, November 18, 2010 - 12:30 - 13:30