Algebraic Bethe ansatz for the supersymmetric U model

We present an algebraic Bethe ansatz for the supersymmetric U model for correlated electrons on the unrestricted 4^L-dimensional electronic Hilbert space ⊗_Lⁿ⁼¹C⁴ (where L is the lattice length). The supersymmetry algebra of the model is the Lie superalgebra gl(2|1) and contains one symmetry-preserving free real parameter which is the Hubbard interaction parameter U. The parameter U arises from the one-parameter family of inequivalent typical four-dimensional irreps of gl(2|1). Eigenstates of the model are determined by the algebraic Bethe ansatz on a one-dimensional periodic lattice. © 1996 The American Physical Society.