Europhys. Lett, 47 (5), pp. 582-587 (1999)
Effect of nonlocal charge correlations on the Mott-Hubbard transition
Max-Planck-Institut für Physik komplexer Systeme
Nöthnitzer Straße 38, D-01187 Dresden, Germany
(received 29 January 1999; accepted in final form 8 July 1999)
PACS. 71.30 - Metal-insulator transitions and other electronic transitions.
PACS. 71.10Hf - Non-Fermi-liquid ground states, electron phase diagrams and phase transitions in model systems.
PACS. 71.27 - Strongly correlated electron systems; heavy fermions.
The Mott-Hubbard transition is studied by examining the metal-insulator transition (MIT) in the homogeneous phase of the two-dimensional spinless Falicov-Kimball model. We use an extension of dynamical mean-field approximation, which allows inclusion of nonlocal correlations. The extension is based on the projection technique and the dynamical mean-field approximation, in which nonlocal contributions to the dynamics of systems are taken into account through static quantities, while the dynamical local contributions are kept by the memory function. We investigate critical behaviours of various dynamic and thermodynamic quantities near the MIT and estimate their critical exponents. The critical exponents obtained support a hyperscaling hypothesis and show a significant influence of nonlocal charge correlations on the transition.
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