Comment on "Charged impurity scattering limited low temperature resistivity of low density silicon inversion layers" (Das Sarma and Hwang, cond-mat/9812216)

In a recent preprint cond-mat/9812216, Das Sarma and Hwang propose an explanation of the sharp decrease in resistivity at low temperatures which has been attributed to a transition to an unexpected conducting phase in dilute high-mobility two-dimensional systems at B=0. In this Comment, we examine whether their model is supported by the available experimental data.