Metal-insulator transition in a low-mobility two-dimensional electron system

We have varied the disorder in a two-dimensional electron system in silicon by applying substrate bias. When the disorder becomes sufficiently low, we observe the emergence of the metallic phase, and find evidence for a metal-insulator transition (MIT): the single-parameter scaling of conductivity with temperature near a critical electron density. We obtain the scaling function β, which determines the length (or temperature) dependence of the conductance, β is smooth and monotonie, and linear in the logarithm of the conductance near the MIT, in agreement with the scaling theory for interacting systems. © 1998 Elsevier Science B.V. All rights reserved.