Dresden 2014 – wissenschaftliches Programm
DY 40.22: Poster
Donnerstag, 3. April 2014, 17:00–19:00, P3
Nonlinear Response in the Driven Lattice Lorentz Gas — •Sebastian Leitmann1,2 and Thomas Franosch1,2 — 1Institut für Theoretische Physik, Leopold-Franzens-Universität Innsbruck, Technikerstraße 25/2, A-6020 Innsbruck, Austria — 2Institut für Theoretische Physik, Friedrich-Alexander-Universität Erlangen-Nürnberg, Staudtstraße 7, 91058 Erlangen, Germany
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.
 Sebastian Leitmann and Thomas Franosch, Phys. Rev. Lett. 111, 190603 (2013).