Peculiar Thermodynamic Properties of the Falicov-Kimball Model for small U Couplings |
| J. Krawczyk and R. Lemański
Institute of Low Temperature and Structure Research, Polish Academy of Sciences, 50-422 Wrocław, Poland |
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| We analyse a behaviour of the order parameter and specific heat of the Falicov-Kimball model (FKM) on the Bethe lattice using the Dynamical Mean Field Theory (DMFT) formalism, which provides the exact solution in the limit of large spatial dimensions. In the large U limit, the FKM maps onto the effective Ising model, with the order parameter of the Curie-Weiss form. However, in the small U limit the order parameter takes on unusual shape, with a sharp reduction near T ≈ Tc/2. We focus our investigation on a crossover between these two limits, thus we perform: our calculations for a set of intermediate and small values of U. We find the overall behaviour of the order parameter and specific heat as a function of temperature to be quite anomalous. |
DOI: 10.12693/APhysPolA.133.369 PACS numbers: 71.10.Fd, 71.20.-b, 71.45.Lr |