Critical Properties of an Integrable Supersymmetric Eletronic Model

TL;DR

This paper explores an integrable supersymmetric electronic model, analyzing its excitations, spectrum, and conformal properties, revealing unique massless and massive behaviors and a central charge of -1.

Contribution

It introduces an integrable extension of the Hubbard model based on a quantum deformed superalgebra and characterizes its physical and conformal properties.

Findings

Charge dispersion exhibits massless and massive behaviors.

Finite-size spectrum indicates a conformal theory with central charge c=-1.

Exact results obtained at the isotropic point without Bethe ansatz.

Abstract

We investigate the physical properties of an integrable extension of the Hubbard model with a free parameter $\gamma$ related to the quantum deformation of the superalgebra $sl(2|2)^{(2)}$. The Bethe ansatz solution is used to determine the nature of the spin and charge excitations. The dispersion relation of the charge branch is given by a peculiar product between energy-momenta functions exhibiting massless and massive behaviors. The study of the finite-size corrections to the spectrum reveals us that the underlying conformal theory has central charge $c=-1$ and critical exponents depending on the parameter $\gamma$. We note that exact results at the isotropic point $\gamma=0$ can be established without recourse to the Bethe ansatz solution.