Volume 85, Number 4, February 2009
Article Number 40003
Number of page(s) 5
Section General
Published online 18 February 2009
EPL, 85 (2009) 40003
DOI: 10.1209/0295-5075/85/40003

Underdamped quantum ratchets

S. Denisov, S. Kohler and P. Hänggi

Institut für Physik, Universität Augsburg - Universitätsstraße 1, D-86135 Augsburg, Germany, EU

received 14 November 2008; accepted in final form 21 January 2009; published February 2009
published online 18 February 2009

We investigate the quantum ratchet effect under the influence of weak dissipation which we treat within a Floquet-Markov master equation approach. A ratchet current emerges when all relevant symmetries are violated. Using time-reversal symmetric driving we predict a purely dissipation-induced quantum ratchet current. This directed quantum transport results from bath-induced superpositions of non-transporting Floquet states.

05.60.Gg - Quantum transport.
37.10.Jk - Atoms in optical lattices.
05.45.Mt - Quantum chaos; semiclassical methods.

© EPLA 2009