Condensed Matter Seminar

Paul Fendley
Univerisity of Virginia

Thursday, May 3, 2007
1:00 pm in SPL 52

Disentanglement by a point contact

Abstract: I discuss the effects of a point contact on systems with gapped bulk excitations and gapless edge modes. Examples include the abelian and non-abelian fractional quantum Hall effects, and p + ip superconductors. Even formulating the problem in non-abelian cases is conceptually and technically non-trivial, because the quasiparticles tunneling at the point contact are entangled. I show in general how to resolve this difficulty and uniquely define the quasiparticle tunneling Hamiltonian; a Kondo-like degree of freedom emerges in the simplest cases. I also explain how the entanglement entropy of both bulk and edge excitations can be encoded in a single "holographic" partition function.