New Spin-Orbit-Induced Universality Class in the Integer Quantum Hall Regime

Using heuristic arguments and numerical simulations it is argued that the critical exponent [Formula presented] describing the localization length divergence at the integer quantum-Hall transition is modified in the presence of spin-orbit scattering with short-range correlations. The exponent is very close to [Formula presented], the percolation correlation length exponent, consistent with the prediction of a semiclassical argument. In addition, a band of weakly localized states is conjectured.