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Breakdown of Luttinger's theorem in two-orbital Mott insulators

A. Rosch
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Abstract

An analysis of Luttinger's theorem shows that -- contrary to recent claims -- it is not valid for a generic Mott insulator. For a two-orbital Hubbard model with two electrons per site the crossover from a non-magnetic correlated insulating phase (Mott or Kondo insulator) to a band insulator is investigated. Mott insulating phases are characterized by poles of the self-energy and corresponding zeros in the Greens functions defining a ``Luttinger surface'' which is absent for band insulators. Nevertheless, the ground states of such insulators with two electrons per unit cell are adiabatically connected.

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A. Rosch. 2007-11-20. Breakdown of Luttinger's theorem in two-orbital Mott insulators. https://doi.org/10.1140/epjb%2Fe2007-00312-3

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