Rectification of current in ac-driven nonlinear systems and symmetry properties of the Boltzmann equation

摘要

We study rectification of a current of particles moving in a spatiallyperiodic potential under the influence of time-periodic forces with zero meanvalue. If certain time-space symmetries are broken a non-zero directed currentof particles is possible. We investigate this phenomenon in the framework ofthe kinetic Boltzmann equation. We find that the attractor of the Boltzmannequation completely reflects the symmetries of the original one-particleequation of motion. Especially, we analyse the limits of weak and strongrelaxation. The dc current increases by several orders of magnitude withdecreasing dissipation.