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Mott Transition in Degenerate Hubbard Models: Application to Doped Fullerenes

Olle Gunnarsson·Erik Koch·Richard M. Martin
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Abstract

The Mott-Hubbard transition is studied for a Hubbard model with orbital degeneracy N, using a diffusion Monte-Carlo method. Based on general arguments, we conjecture that the Mott-Hubbard transition takes place for U/W \propto \sqrt{N}, where U is the Coulomb interaction and W is the band width. This is supported by exact diagonalization and Monte-Carlo calculations. Realistic parameters for the doped fullerenes lead to the conclusion that stoichiometric A_3 C_60 (A=K, Rb) are near the Mott-Hubbard transition, in a correlated metallic state.

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Olle Gunnarsson, Erik Koch, Richard M. Martin. 1996-08-23. Mott Transition in Degenerate Hubbard Models: Application to Doped Fullerenes. https://doi.org/10.1103/physrevb.54.r11026

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