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 $\nu =1.3\mathrm{}\pm 0.2$. The level statistics at the critical point are also analyzed and shown to be scale independent. The form of the energy level spacing distribution $P\left(s\right)$ 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.