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arXiv · 0710.5842

Fermionic systems with charge correlations on the Bethe lattice

Ferdinando Mancini·Adele Naddeo
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Abstract

A fermionic model, built up of q species of localized Fermi particles, interacting by charge correlations, is isomorphic to a spin-q/2 Ising model. However, the equivalence is only formal and the two systems exhibit a different physical behavior. By considering a Bethe lattice with q=1, we have exactly solved the models. There exists a critical temperature below which there is a spontaneous breakdown of the particle-hole symmetry for the first model, and of the spin symmetry for the second. While the spin system is always stable and exhibits a homogeneous ferromagnetic phase below T_{c}, the fermionic system for T<T_{c} is unstable against the formation of inhomogeneous phases with charge separation.

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Ferdinando Mancini, Adele Naddeo. 2007-10-31. Fermionic systems with charge correlations on the Bethe lattice. https://doi.org/10.1016/j.physc.2007.03.213

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