Investigation of the zero-field 2D “metallic” state with rS and kFl controlled independently

We compare the rise in resistivity with increasing temperature in the “metallic” regime for a range of electron densities and for several values of substrate bias. This allows the strength of Coulomb interactions (rS) and of disorder (1/kFl) to be controlled independently. For temperatures well below the Fermi temperature, our data obey a scaling law where kFl, and not rS, is the crucial parameter, suggesting that the “metallic” state is not a novel state caused by interactions.