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Reentrant charge order transition in the extended Hubbard model

R. Pietig·R. Bulla·S. Blawid
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Abstract

We study the extended Hubbard model with both on-site and nearest neighbor Coulomb repulsion ($U$ and $V$, respectively) in the Dynamical Mean Field theory. At quarter filling, the model shows a transition to a charge ordered phase with different sublattice occupancies $n_A \nen_B$. The effective mass increases drastically at the critical $V$ and a pseudo-gap opens in the single-particle spectral function for higher values of $V$. The $V_c(T)$-curve has a negative slope for small temperatures, i.e. the charge ordering transition can be driven by increasing the temperature. This is due to the higher spin-entropy of the charge ordered phase.

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R. Pietig, R. Bulla, S. Blawid. 1999-01-05. Reentrant charge order transition in the extended Hubbard model. https://doi.org/10.1103/physrevlett.82.4046

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