Electronic polarons in an extended Falicov-Kimball modelP. 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.
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