An extended supersymmetric t-J model

A new lattice model is presented for correlated electrons on the unrestricted 4(L)-dimensional electronic IIilbert space +(L)(n=1) C-4 (where L is the lattice length). It is an extension of tile supersymmetric t-J model. The new model has gl(2/1) supersymmetry and contains one symmetry-preserving free real parameter alpha which has its origin ill tile one-parameter family of inequivalent typical 4-dimensional irreps of gl(2/1). When alpha = 0, the model reduces to the supersymmetric t-J model