Optical conductivity of the Hubbard model at finite temperature

Abstract

The optical conductivity, $\sigma (\omega )$, of the two dimensional one-band Hubbard model is calculated at finite temperature using exact diagonalization techniques on finite clusters. The in-plane d.c. resistivity, ${\rho }_{ab}$, is also evaluated. We find that at large U/t and temperature T, ${\rho }_{ab}$ is approximately linear with temperature, in reasonable agreement with experiments on high-T${}_c$ superconductors. Moreover, we note that $\sigma (\omega )$ displays charge excitations, a mid-infrared (MIR) band and a Drude peak, also as observed experimentally. The combination of the Drude peak and the MIR oscillator strengths leads to a conductivity that decays slower than $1/{\omega }^2$ at energies smaller than the insulator gap near half-filling.

12 pages, 3 figures appended, Revtex version 2.0, preprint

References in corpus (2)

• Correlated Electrons in High Temperature Superconductors
• Dynamical Properties of a Single Hole in an Antiferromagnet

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