$XXZ$ model as effective Hamiltonian for generalized Hubbard models with broken $η$-symmetry

G. Albertini; V. E. Korepin; A. Schadschneider

doi:10.1088/0305-4470/28/10/004

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$XXZ$ model as effective Hamiltonian for generalized Hubbard models with broken $η$-symmetry

G. Albertini·V. E. Korepin·A. Schadschneider

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Abstract

We consider the limit of strong Coulomb attraction for generalized Hubbard models with $η$-symmetry. In this limit these models are equivalent to the ferromagnetic spin-1/2 Heisenberg quantum spin chain. In order to study the behaviour of the superconducting phase in the electronic model under perturbations which break the $η$-symmetry we investigate the ground state of the ferromagnetic non-critical $XXZ$-chain in the sector with fixed magnetization. It turns out to be a large bound state of $N$ magnons. We find that the perturbations considered here lead to the disappearance of the off-diagonal longe-range order.

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G. Albertini, V. E. Korepin, A. Schadschneider. 1995-01-10. $XXZ$ model as effective Hamiltonian for generalized Hubbard models with broken $η$-symmetry. https://doi.org/10.1088/0305-4470%2F28%2F10%2F004

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