title: Nonlinear response in the driven lattice Lorentz gas.
abstract: We determine the nonlinear time-dependent response of a tracer on a lattice with randomly distributed hard obstacles as a force is switched on. The calculation is exact to first order in the obstacle density and holds for arbitrarily large forces. Whereas, on the impurity-free lattice, the nonlinear drift velocity in the stationary state is analytic in the driving force, interactions with impurities introduce logarithmic contributions beyond the linear regime. The long-time decay of the velocity toward the steady state is exponentially fast for any finite value of the force, in striking contrast to the power-law relaxation predicted within linear response. We discuss the range of validity of our analytic results by comparison to stochastic simulations.
authors.affiliation: Institut für Theoretische Physik, Leopold-Franzens-Universität Innsbruck, Technikerstraße 25/2, A-6020 Innsbruck, Austria and Institut für Theoretische Physik, Friedrich-Alexander-Universität Erlangen-Nürnberg, Staudtstraße 7, 91058 Erlangen, Germany.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Leitmann
authors.forename: Thomas
authors.initials: T
authors.lastname: Franosch