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arXiv · 1006.1855

Electron energy spectrum of the spin-liquid state in a frustrated Hubbard model

A. E. Antipov·A. N. Rubtsov·M. I. Katsnelson·A. I. Lichtenstein
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Abstract

Non-local correlation effects in the half-filled Hubbard model on an isotropic triangular lattice are studied within a spin polarized extension of the dual fermion approach. A competition between the antiferromagnetic non-collinear and the spin liquid states is strongly enhanced by an incorporation of a k-dependent self-energy beyond the local dynamical mean-field theory. The dual fermion correc- tions drastically decrease the energy of a spin liquid state while leaving the non-collinear magnetic states almost non-affected. This makes the spin liquid to become a preferable state in a certain interval of interaction strength of an order of the magnitude of a bandwidth. The spectral function of the spin-liquid Mott insulator is determined by a formation of local singlets which results in the energy gap of about twice larger than that of the 120 degrees antiferromagnetic Neel state.

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A. E. Antipov, A. N. Rubtsov, M. I. Katsnelson, A. I. Lichtenstein. 2010-12-24. Electron energy spectrum of the spin-liquid state in a frustrated Hubbard model. https://doi.org/10.1103/physrevb.83.115126

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