DIMER-HOLE-RVB STATE OF THE 2-LEG T-J LADDER - A RECURRENT VARIATIONAL ANSATZ

We present a variational treatment of the ground state of the two-leg t-J ladder, which combines the dimer and the hard-core boson models in to one effective model. This model allows us to study the local struct ure of the hole pairs as a function of doping. A second-order recursio n relation is used to generate the variational wave function, which su bstantially simplifies the computations. We obtain good agreement with numerical density matrix renormalization group results for the ground state energy in the strong-coupling regime. We find that the local st ructure of the pairs depends upon whether the ladder is slightly or st rongly dopped.