Electronic polarons in an extended Falicov-Kimball model

¹ Department of Theoretical Physics, Institute of Advanced Studies The Australian National University, Canberra, ACT 0200, Australia
² Theoretical Division, Los Alamos National Laboratory - Los Alamos, NM 87545, USA

Received: 7 November 2005
Accepted: 13 February 2006

Abstract

We examine the one-dimensional spinless Falicov-Kimball model extended by a hybridization potential between the localized and itinerant electron states. Below half-filling we find a crossover from a mixed-valence metal to an integer-valence phase-separated state with increasing on-site Coulomb repulsion. This crossover regime is characterized by local competition between the strong- and weak-coupling behaviour, manifested by the formation of an electronic polaron liquid. A phase diagram is presented and discussed in detail.