Metallic behavior in dilute two-dimensional hole systems - art. no. 126802

We have studied the metallic behavior in low-density two-dimensional p-GaAs systems, close to the apparent metal-insulator transition. Two observation s are made concerning the origins of the metallic-like behavior. Within a g iven sample the strength of the metallic behavior is almost independent of the asymmetry of the confining potential, and is predominantly determined b y the low-temperature resistivity (i.e., by k(F)l). In all our samples we f ind that at low densities, close to the transition from insulating to metal lic behavior, the fractional decrease in conductivity with increasing tempe rature scales as T/T-F.