Dephasing Time in Disordered Systems

We show that interaction effects give rise to a cutoff $\frac{1}{{\tau }_{\mathrm{ph}}}$ in the "diffusion," the basic propagator of the disordered interacting electron gas. We calculate $\frac{1}{{\tau }_{\mathrm{ph}}}$ to lowest order in the disorder but to all orders in the interaction, and exhibit its relation to the scaling variables of the disordered-interacting-electron problem. This framework provides an explanation for the anomalous enhancement of inelastic processes which is observed experimentally in systems close to the metal-insulator transition.