CANONICAL PHASE-DIAGRAMS OF THE 1D FALICOV-KIMBALL MODEL AT T=O

The Falicov-Kimball model of spinless quantum electrons hopping on a 1 -dimensional lattice and of immobile classical ions occupying some lat tice sites, with only intrasite coupling between those particles, have been studied at zero temperature by means of well-controlled numerica l procedures, For selected values of the unique coupling parameter U t he restricted phase diagrams (based on all the periodic configurations of localized particles (ions) with period not greater than 16 lattice constants, typically) have been constructed in the grand-canonical en semble. Then these diagrams have been translated into the canonical en semble, Compared to the diagrams obtained in other studies our ones co ntain more details, in particular they give better insight into the wa y the mixtures of periodic phases are formed, Our study has revealed s everal families of new characteristic phases like the generalized most homogeneous and the generalized crenel phases, a first example of a s tructural phase transition and a tendency to build up an additional sy mmetry - the hole-particle symmetry with respect to the ions (electron s) only, as U decreases.