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arXiv · 1302.1437

Optimal Hubbard models for materials with nonlocal Coulomb interactions: graphene, silicene and benzene

M. Schüler·M. Rösner·T. O. Wehling·A. I. Lichtenstein·M. I. Katsnelson
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Abstract

To understand how nonlocal Coulomb interactions affect the phase diagram of correlated electron materials, we report on a method to approximate a correlated lattice model with nonlocal interactions by an effective Hubbard model with on-site interactions U* only. The effective model is defined by the Peierls-Feynman-Bogoliubov variational principle. We find that the local part of the interaction U is reduced according to U*=U-V', where V' is a weighted average of nonlocal interactions. For graphene, silicene and benzene we show that the nonlocal Coulomb interaction can decrease the effective local interaction by more than a factor of 2 in a wide doping range.

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M. Schüler, M. Rösner, T. O. Wehling, A. I. Lichtenstein, M. I. Katsnelson. 2013-02-06. Optimal Hubbard models for materials with nonlocal Coulomb interactions: graphene, silicene and benzene. https://doi.org/10.1103/physrevlett.111.036601

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