GROUND-STATE PROPERTIES OF THE DEGENERATE SUPERSYMMETRIC T-J MODEL WITH CRYSTALLINE FIELD SPLITTING IN ONE-DIMENSION

The one-dimensional t-J model is considered, consisting of electrons w ith four spin-components on a lattice with nearest neighbor hopping t constrained by the excluded multiple occupancy of the sites, exchange J between neighboring sites and a crystal field splitting DELTA. This model is integrable at the supersymmetric point. The exact solution is presented via Bethe's ansatz and groundstate properties as a function of DELTA are discussed. The model could correspond to a two-band situ ation with one band being the z2 and the other one the x2-y2 orbitals of Cu2+.