Possible Explanation of Nonlinear Conductivity in Thin-Film Metal Wires

We introduce the idea of an incoherence length L₂ at which inelastic collision broadening equals electronic energy-level separation. The two-dimensional conductance crosses over at L₂ from a lnL dependence suggested recently by Abrahams et al. to Ohmic behavior. These ideas and plausible relaxation and heating models are used to explain the nonlinear conductivity observations of Dolan and Osheroff.