Condensed Matter Physics Seminar
2 p.m., Thursday, April 26, 2007
Room 1201, Physics Building
Pseudogaps and Fermi arcs:A cluster dynamical mean field theory
description of Mottness
Tudor Stanescu
(CMTC, University of Maryland)
Abstract: Within the Hubbard model, we investigate the properties
of a strongly correlated metal in the proximity of a Mott insulating phase,
using a cluster generalization of the dynamical mean field theory. We find that
short range correlations determine the opening of a Mott gap at half filling and
the appearance on a kdependent pseudogap at finite doping. When the gaps are
opened, the system is characterized by a divergence of the zero frequency
electron selfenergy at certain momenta in the Brillouin zone corresponding to a
surface of zeros of the single particle Green function. The interplay between
this surface of zeros and the surface of infinities (the Fermi surface) leads to
the appearance of Fermi arcs. In the superconducting state, we find that the
photoemission energygap can be naturally decomposed into two components: one is
generated by dwave superconductivity and formally described by the anomalous
selfenergy, wile the other, stemming from the proximity of the Mott insulator,
is described by the normal selfenergy and evolves into the normalstate
pseudogap. In the underdoped regime the first component dominates the nodal
points and decreases with decreasing doping, while the second dominates the
antinodes and has an opposite doping dependence.

Host: Galitski
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