TEMPERATURE-DEPENDENCE OF THE CONDUCTIVITY AND MINIMUM QUANTUM MOBILITY OF A HIGHLY DISORDERED DILUTE 2-DIMENSIONAL ELECTRON-GAS

We report the first observations of magnetic-field-independent corrections to the conductivity in gas atom scattering of electrons on solid H-2. These incoherent corrections, which are substantially larger than the weak-localization terms at high impurity densities, are estimated via an electron-trapping model. The model has essentially no adjustable parameters and gives a self-consistent extrapolation between the week-and strong-disorders limits. In the regime in which trapping is dominant we observe a residual electron mobility mu-res approximately T(-1) associated with a lower quantum limit of diffusion.