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Influence of Hybridization on the Properties of the Spinless Falicov-Kimball Model

G. Czycholl
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Abstract

Without a hybridization between the localized f- and the conduction (c-) electron states the spinless Falicov-Kimball model (FKM) is exactly solvable in the limit of high spatial dimension, as first shown by Brandt and Mielsch. Here I show that at least for sufficiently small c-f-interaction this exact inhomogeneous ground state is also obtained in Hartree-Fock approximation. With hybridization the model is no longer exactly solvable, but the approximation yields that the inhomogeneous charge-density wave (CDW) ground state remains stable also for finite hybridization V smaller than a critical hybridization V_c, above which no inhomogeneous CDW solution but only a homogeneous solution is obtained. The spinless FKM does not allow for a ''ferroelectric'' ground state with a spontaneous polarization, i.e. there is no nonvanishing $ $-expectation value in the limit of vanishing hybridization.

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G. Czycholl. 1998-05-27. Influence of Hybridization on the Properties of the Spinless Falicov-Kimball Model. https://doi.org/10.1103/physrevb.59.2642

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