Transport signatures of strong spin-orbit coupling in two-dimensional materials

We discuss the transport properties of two-dimensional materials with spin-orbit (SO) coupling and disorder focusing on the unprecedented ultrastrong SO regime, where the SO energy is the largest energy scale in the system. We show that in this regime Born conductivity displays substantial deviations from the usual Drude law, with a strongly density-dependent mobility. Along with numerics, we present simple but accurate analytical formulae which, beside shedding new light on recent experiments on oxide interfaces, may provide a powerful tool to asses the strength of SO coupling in a transport measurement.