Spectral kinks and mid-infrared optical conductivity of doped Mott insulators from strong electron correlations

Shiladitya Chakraborty, Dimitrios Galanakis, Philip W Phillips

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Abstract

We compute the one-particle spectral function and the optical conductivity for the two-dimensional Hubbard model on a square lattice. The computational method is cellular dynamical mean-field theory in which a four-site Hubbard plaquette is embedded in a self-consistent bath. We obtain a "kink" feature in the dispersion of the spectral function and a mid-infrared (mid-IR) absorption peak in the optical conductivity, consistent with experimental data. Of the 256 plaquette states, only a single state which has d x2 - y2 symmetry contributes to the mid-IR, thereby suggesting a direct link with the pseudogap. Local correlations between doubly and singly occupied sites which lower the kinetic energy of a hole are the efficient cause of this effect.

Original languageEnglish (US)
Article number212504
JournalPhysical Review B - Condensed Matter and Materials Physics
Volume78
Issue number21
DOIs
StatePublished - Dec 1 2008

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ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics

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