CURRENT RELAXATION IN DISORDERED ONE-DIMENSIONAL AND 2-DIMENSIONAL SYSTEMS

The current relaxation of disordered one- and two-dimensional systems is treated on the basis of a self-consistent approach for the diffusion coefficient. At the predicted delocalization field strength a long-time power law decay of the current is observed according to j(t) congruent-to t-1/2 if inelastic scattering processes are neglected. This slow current relaxation should be measurable in one-dimensional systems. The experimental verification of the results for a two-dimensional electron gas is complicated on account of the fact that both the delocalization field strength and the characteristic decay time depend exponentially on the disorder parameter. The measurement of the slow 2D current relaxation requires very low carrier densities and extremely low temperatures.