Weak-localization type description of conduction in the

This paper is devoted to the temperature dependence of the resistivity in high mobility SiMOSFET samples over the wide range of densities in the “metallic phase” (n > nc) but not too close to the critical density nc. Three domains of qualitatively different behavior in �(T) are identified. These are: [i] “quantum domain” (T 0); and [ii] “crossover domain” between the former two (Tq 0). For high mobility Si-MOS samples we find empirically Tq ∼ 0.007EF and Tcros ∼ 0.07EF. In the crossover regime and at higher densities (> 20 × 10 11 cm 2 ), �(T) goes through a minimum at temperature Tmin. Both the absolute value of Tmin and its dependence on the carrier concentration are found to be in a reasonable agreement with the conventional weaklocalization theory. For densities smaller than ∼ 20×10 11 cm 2 , the theoretical estimate for Tmin falls outside the experimentally accessible temperature range. This explains the absence of the minimum at these densities in the data. In total, over the two decades in the temperature (domains [ii] and [iii]), the two semiclassical effects mentioned above mimic the metallic like transport properties. Our analysis shows that the behaviour of resistivity �(T) in the region of � ≪ h/e 2 can be described phenomenologically in terms of the conventional weak-localization theory.