Intermediate Coupling Theory of Electronic Ferroelectricity

Intermediate coupling theory of electronic ferroelectricity.

We calculate the quantum phase diagram of an extended Falicov-Kimball model for one- and two-dimensional systems in the intermediate coupling regime. Even though some features of the phase diagram are obtained analytically, the main results are calculated with a constrained path Monte Carlo technique. We find that this regime is dominated by a Bose-Einstein condensation of excitons with a built...

Weak-coupling Treatment of Electronic (Anti-)Ferroelectricity in the Extended Falicov-Kimball Model

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 conductionand f-bands different kinds of ordered solutions are possible, namely charge-density wave (CDW) order, electronic ferro...

Spectral Functions of the Falicov-Kimball Model with Electronic Ferroelectricity

Theory of thermal spin-charge coupling in electronic systems

The interplay between spin transport and thermoelectricity offers several novel ways of generating, manipulating, and detecting nonequilibrium spin in a wide range of materials. Here, we formulate a phenomenological model in the spirit of the standard model of electrical spin injection to describe the electronic mechanism coupling charge, spin, and heat transport and employ the model to analyze...

Coupling Between Spins and Phonons Towards Ferroelectricity in Magnetoelectric Systems