2-DIMENSIONAL RANDOM-NETWORK MODEL WITH SYMPLECTIC SYMMETRY

We construct a two-dimensional network model with symplectic symmetry. This model corresponds to the Chalker-Coddington network model for a quantum Hall system. We calculate the transfer matrix numerically and find that the Anderson transition exists in the model. The localizatio n length exponent nu is estimated to be 2.88+/-0.15. This value is con sistent with Fastenrath's results of a tight-binding Hamiltonian with spin-orbit coupling. [S0163-1829(98)08236-8].