Extended Hubbard model: Charge ordering and Wigner–Mott transition

A. AMARICCI; A. CAMJAYI; D. TANASKOVIC; K. HAULE; V. DOBROSAVLJEVIC; G. KOTLIAR

PHYSICAL REVIEW B - CONDENSED MATTER AND MATERIALS PHYSICS

AMER PHYSICAL SOC

Año: 2010 vol. 82 p. 155102 - 155102

0163-1829

Strong correlations effects, which are often associated to the approach to a Mott insulating state, in some cases may be observed even far from half filling. This typically happens whenever the intersite Coulomb repulsion induces a tendency toward charge ordering, an effect that confines the electrons, and in turn favors local moment formation, i.e., Mott localization. A distinct intermediate regime then emerges as a precursor of such a Wigner-Mott transition, which is characterized by both charge and spin correlations, displaying large mass enhancements and strong renormalizations of other Fermi-liquid parameters. Here we present a careful study of a quarter-filled extended Hubbard model—a simple example where such physics can be studied in detail, and discuss its relevance for the understanding of the phenomenology of low-density two-dimensional electron gases.