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arXiv · 1008.1272

Approximate solution of variational wave functions for strongly correlated systems: Description of bound excitons in metals and insulators

Balazs Hetenyi
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Abstract

An approximate solution scheme, similar to the Gutzwiller approximation, is presented for the Baeriswyl and the Baeriswyl-Gutzwiller variational wavefunctions. The phase diagram of the one-dimensional Hubbard model as a function of interaction strength and particle density is determined. For the Baeriswyl wavefunction a metal-insulator transition is found at half-filling, where the metallic phase ($U U_c$ phase displays a finite Fermi step, as well as double occupations originating from bound excitons. As the filling is changed away from half-filling bound excitons are supressed. For the Baeriswyl-Gutzwiller wavefunction at half-filling a metal-insulator transition between the correlated metallic and excitonic insulating state is found. Away from half-filling bound excitons are suppressed quicker than for the Baeriswyl wavefunction.

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Balazs Hetenyi. 2010-09-04. Approximate solution of variational wave functions for strongly correlated systems: Description of bound excitons in metals and insulators. https://doi.org/10.1103/physrevb.82.115104

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