New Supersymmetric and Exactly Solvable Model of Correlated Electrons.

A new lattice model is presented for correlated electrons on the unrestricted 4L-dimensional electronic Hilbert space n=1LC4 (where L is the lattice length). It is a supersymmetric generalization of the Hubbard model, but differs from the extended Hubbard model proposed by Essler, Korepin, and Schoutens. The supersymmetry algebra of the new model is superalgebra gl(2 |1). The model contains one symmetry-preserving free real parameter which is the Hubbard interaction parameter U, and has its origin here in the one-parameter family of inequivalent typical 4-dimensional irreducible representations of gl(2 |1). On a one-dimensional lattice, the model is exactly solvable by the Bethe ansatz.