Anderson transition in three-dimensional disordered systems with symplectic symmetry

The Anderson transition in a 3D system with symplectic symmetry is investigated numerically. From a one-parameter scaling analysis the critical exponent nu of the localization length is extracted and estimated to be nu 1.3 +/- 0.2. The level statistics at the critical point are also analyzed and shown to be scale independent. The form of the energy level spacing distribution P(s) at the critical point is found to be different from that for the orthogonal ensemble, suggesting that the breaking of spin rotation symmetry is relevant at the critical point.