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Density-Matrix functional theory of strongly-correlated lattice fermions

R. Lopez-Sandoval·G. M. Pastor
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Abstract

A density functional theory (DFT) of lattice fermion models is presented, which uses the single-particle density matrix gamma_{ij} as basic variable. A simple, explicit approximation to the interaction-energy functional W[gamma] of the Hubbard model is derived from exact dimer results, scaling properties of W[gamma] and known limits. Systematic tests on the one-dimensional chain show a remarkable agreement with theBethe-Ansatz exact solution for all interaction regimes and band fillings. New results are obtained for the ground-state energyand charge-excitation gap in two dimensions. A successful description of strong electron correlations within DFT is achieved.

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R. Lopez-Sandoval, G. M. Pastor. 2002-07-17. Density-Matrix functional theory of strongly-correlated lattice fermions. https://doi.org/10.1103/physrevb.66.155118

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