Level statistics in a two-dimensional system with strong spin-orbit coupling - art. no. 113301

We study level correlations in a two-dimensional system with a long-range r andom potential and strong spin-orbit (SO) splitting Delta (SO) of the spec trum. The level correlations for sufficiently large Delta (SO) are shown to be described by orthogonal Wigner-Dyson statistics, in contrast to the com mon point of view that a system with the strong SO coupling belongs to the symplectic statistical ensemble. We demonstrate also that in a wide energy interval the level statistics is completely determined by transitions betwe en two branches of the split spectrum.