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Metal-insulator transition and charge ordering in the extended Hubbard model at one-quarter filling

M. Calandra·J. Merino·Ross H. McKenzie
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Abstract

We study with exact diagonalization the zero temperature properties of the quarter-filled extended Hubbard model on a square lattice. We find that increasing the ratio of the intersite Coulomb repulsion, $V$, to the band width drives the system from a metal to a charge ordered insulator. The evolution of the optical conductivity spectrum with increasing $V$ is compared to the observed optical conductivity of several layered molecular crystals with the theta and beta'' crystal structures.

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M. Calandra, J. Merino, Ross H. McKenzie. 2002-02-13. Metal-insulator transition and charge ordering in the extended Hubbard model at one-quarter filling. https://doi.org/10.1103/physrevb.66.195102

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