Europhys. Lett.
Volume 74, Number 1, April 2006
Page(s) 131 - 137
Section Condensed matter: electronic structure, electrical, magnetic, and optical properties
Published online 01 March 2006
Europhys. Lett., 74 (1), pp. 131-137 (2006)
DOI: 10.1209/epl/i2005-10509-0

Electronic polarons in an extended Falicov-Kimball model

P. M. R. Brydon1, M. Gulácsi1 and A. R. Bishop2

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 in final form 13 February 2006
published online 1 March 2006

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.

71.28.+d - Narrow-band systems; intermediate-valence solids.
71.27.+a - Strongly correlated electrons systems; heavy fermions.

© EDP Sciences 2006