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Delocalizing effect of the Hubbard repulsion for electrons on a two-dimensional disordered lattice

Bhargavi Srinivasan·Giuliano Benenti·Dima L. Shepelyansky
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Abstract

We study numerically the ground-state properties of the repulsive Hubbard model for spin-1/2 electrons on two-dimensional lattices with disordered on-site energies. The projector quantum Monte Carlo method is used to obtain very accurate values of the ground-state charge density distributions with $N_p$ and $N_p+1$ particles. The difference in these charge densities allows us to study the localization properties of an added particle. The results obtained at quarter-filling on finite clusters show that the Hubbard repulsion has a strong delocalizing effect on the electrons in disordered 2D lattices. However, numerical restrictions do not allow us to reach a definite conclusion about the existence of a metal-insulator transition in the thermodynamic limit in two-dimensions.

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Bhargavi Srinivasan, Giuliano Benenti, Dima L. Shepelyansky. 2003-01-31. Delocalizing effect of the Hubbard repulsion for electrons on a two-dimensional disordered lattice. https://doi.org/10.1103/physrevb.67.205112

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