Weak-coupling treatment of electronic (anti-)ferroelectricity in the extended Falicov-Kimball model
Institute for Theoretical Physics, University of Bremen, 28334 Bremen, Germany
Corresponding author: a email@example.com
Revised: 12 June 2008
Published online: 16 July 2008
We study the (spinless) Falicov-Kimball model extended by a finite band width (hopping tf) of the localized (f-) electrons in infinite dimensions in the weak-coupling limit of a small local interband Coulomb correlation U for half filling. In the case of overlapping conduction- and f-bands different kinds of ordered solutions are possible, namely charge-density wave (CDW) order, electronic ferroelectricity (EFE) and electronic antiferroelectricity (EAFE). The order parameters are calculated as a function of the model parameters and of the temperature. There is a first-order phase transition from the CDW-phase to the EFE- or EAFE-phase. The total energy is calculated to determine the thermodynamically stable solution. The quantum phase diagrams are calculated.
PACS: 71.30.+h – Metal-insulator transitions and other electronic transitions / 71.28.+d – Narrow-band systems; intermediate-valence solids / 71.27.+a – Strongly correlated electron systems; heavy fermions
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2008