Scaling behavior in amorphous and disordered metals

We show that the low-temperature resistivity of amorphous and disordered metals is described by a square-root variation with temperature, as suggested by various scaling theories of the metal-insulator transition. The coefficient $\Delta$ (the correlation gap) has the identical dependence on resistivity, $\Delta \sim {\rho }^{-2\mathrm{}}$, reported for materials with resistivity up to three orders of magnitude greater.