The Influence of Lattice Defects on the Ground-State Properties of the Falicov-Kimball Model in Two Dimensions
M. Žonda, P. Farkašovský and H. Čenčariková
Institute of Experimental Physics, Slovak Academy of Sciences, Watsonová47, 041 01 Košice, Slovakia
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Received: 9 07 2007;
The influence of lattice defects (vacancies) on the ground-state properties of the spinless Falicov-Kimball model is studied by a well-controlled numerical method in two dimensions. It is shown that in the presence of vacancies (distributed randomly) the ground states of the Falicov-Kimball model are phase separated for small f-electron concentrations nf and exhibit the long-range order for nf near the half-filled band case nf=1/2. In addition, the dependence of average f-orbital occupancy on the concentration of vacancies is calculated for a wide range of model parameters. The resultant behaviours are used to interpret the experimental data obtained for the mixed-valence system Sm1-xB6.
DOI: 10.12693/APhysPolA.113.291
PACS numbers: 75.10.Lp, 71.27.+a, 71.28.+d, 71.30.+h