Instability of the chiral phase and electronic ferroelectricity in the extended Falicov--Kimball model

Abstract

We consider a spinless extended Falicov--Kimball model at half-filling, for the case of opposite-parity bands. Within the Hartree--Fock approach, we calculate the excitation energies in the chiral phase, which is a possible mean-field solution in the presence of a hybridisation. It is shown that the chiral phase is unstable. We then briefly review the accumulated results on stability and degeneracies of the excitonic insulator phase. Based on these, we conclude that the presence of both hybridisation and narrow-band hopping is required for electronic ferroelectricity.

5 pages, LaTeX, 1 PostScript figure, misprint corrected. Phys. Status Solidi B, in press

References in corpus (2)

• Weak-coupling Treatment of Electronic (Anti-)Ferroelectricity in the Extended Falicov-Kimball Model
• Hartree-Fock study of electronic ferroelectricity in the Falicov-Kimball model with $f$-$f$ hopping

Cited by in corpus (1)

• Unsupervised Machine Learning Phase Classification for Falicov-Kimball Model