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arXiv · 1109.0162

High-energy pseudogap in degenerate Hubbard model induced via Hund coupling

Ansgar Liebsch
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Abstract

Hund coupling in the degenerate five-band Hubbard model near n=6 occupancy is shown to give rise to a significant depletion of spectral weight above the Fermi level. Calculations within dynamical mean field theory combined with exact diagonalization reveal that this pseudogap is associated with a collective mode in the self-energy caused by spin fluctuations. The pseudogap is remarkably stable over a wide range of Coulomb and exchange energies, but disappears for weak Hund coupling. The implications of this phenomenon for optical spectra of iron pnictides are discussed.

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Ansgar Liebsch. 2011-09-01. High-energy pseudogap in degenerate Hubbard model induced via Hund coupling. https://doi.org/10.1103/physrevb.84.180505

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