Optimum ground states for spin-3/2 ladders with two legs

We construct the exact ground state for an antiferromagnetic spin-3/2 model on the two-leg ladder as an optimum ground stare. The ground state contain s a discrete parameter sigma = +/-1 and a continuous parameter a which cont rols z-axis anisotropy. For most values of a the global ground state is uni que. It has vanishing sublattice magnetization and exponentially decaying c orrelation functions. By using the transfer matrix technique, we calculate exactly the fluctuations of the magnetization, the nearest-neighbour correl ation, and the longitudinal correlation length as functions of the paramete rs.