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The European Physical Journal BISSN: 1434-6028 (printed version) Abstract Volume 4 Issue 4 (1998) pp 447-457 Strongly correlated Falicov-Kimball model in infinite dimensions
B.M. Letfulov (a)
Institute of Metal Physics, Ural division of Russian Academy of Sciences, Kovalevskaya str. 18, Ekaterinburg, 620219, Russia Received: 15 October 1997 / Accepted: 11 March 1998 Abstract: In this paper we have examined the strongly correlated Falicov-Kimball model in infinite dimensions with the help of a diagrammatic technique for the Hubbard X-operators. This model is represented by the simplified t-J model with introduced intra-atomic level energy $\varepsilon^0$for localized particles. For the Bethe lattice with $z\to\infty$, we have found that the obtained equations for the band Green's function and self-energy coincide with the corresponding Brandt-Mielsch equations taken at $U\to\infty$, and are resolved in analytical form both in the homogeneous phase and in the chessboard phase. In the latter case we have obtained the equation for the order parameter defining the chessboard-like distribution of localized particles. Instability of the homogeneous phase and properties of the chessboard phase are investigated in detail. In particular, it is found that the temperature dependence of the chessboard order parameter has reentrant behaviour for some range of values of $\varepsilon^0$.
PACS. 71.10.Fd Lattice fermion models (Hubbard model, etc.) - 71.45.Lr Charge-density-wave systems
(a) email: Barri.Letfulov@imp.uran.ru Article in PDF-Format (458 KB) Online publication: August 27, 1998 |