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arXiv · 1711.04100

Single-particle properties of the Hubbard model in a novel three-pole approximation

Andrea Di Ciolo·Adolfo Avella
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Abstract

We study the 2D Hubbard model using the Composite Operator Method within a novel three-pole approximation. Motivated by the long-standing experimental puzzle of the single-particle properties of the underdoped cuprates, we include in the operatorial basis, together with the usual Hubbard operators, a field describing the electronic transitions dressed by the nearest-neighbor spin fluctuations, which play a crucial role in the unconventional behavior of the Fermi surface and of the electronic dispersion. Then, we adopt this approximation to study the single-particle properties in the strong coupling regime and find an unexpected behavior of the van Hove singularity that can be seen as a precursor of a pseudogap regime.

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Andrea Di Ciolo, Adolfo Avella. 2017-11-11. Single-particle properties of the Hubbard model in a novel three-pole approximation. https://doi.org/10.1016/j.physb.2017.09.051

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