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The one-electron Green's function of the half-filled Hubbard model on a triangular lattice

M. C. Refolio·J. M. Lopez Sancho·J. Rubio
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Abstract

The one-electron density of states for the half-filled Hubbard model on a triangular lattice is studied as a function of both temperature and Hubbard U using Quantum Monte Carlo. We find three regimes: (1) a strong-coupling Mott-Hubbard regime, characterized by a gap which persists even at high temperatures; (2) a weak-coupling paramagnetic regime, characterized by the absence of a pseudogap at any finite temperature; and (3) an intermediate-coupling (spiral) spin-density-wave regime, characterized by a pseudogap which appears when U is increased beyond a critical (temperature dependent) value. The behavior of the sqrt(3) times sqrt{3} adlayer structures on fourth-group semiconductor surfaces is briefly commented upon in the light of the above discussion.

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M. C. Refolio, J. M. Lopez Sancho, J. Rubio. 2001-03-22. The one-electron Green's function of the half-filled Hubbard model on a triangular lattice. https://arxiv.org/abs/cond-mat/0103459

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