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Electronic Ferroelectricity in the Falicov-Kimball Model

C. D. Batista
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Abstract

I show that a spontaneous electric polarization is developed in the solution of the Falicov-Kimball model (FKM) by mapping the strong coupling limit of the model into an $xxz$ spin 1/2 model with a magnetic field. In this way, I can determine the phase diagram of the strongly interacting model that shows a transition to a mixed valence regime containing two phases: orbital ordering and Bose-Einstein condensation of excitons with a built in electric polarization. The results are extended to the intermeditate and weak coupling regimes.

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C. D. Batista. 2004-02-26. Electronic Ferroelectricity in the Falicov-Kimball Model. https://doi.org/10.1103/physrevlett.89.166403

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