Stuttgart 2012 – wissenschaftliches Programm
Q 35.6: Poster
Mittwoch, 14. März 2012, 16:30–19:00, Poster.I+II
Dynamics of Atoms in a Hamiltonian Quantum Ratchet — •Martin Leder, Tobias Burgermeister, Tobias Salger, Sebastian Kling, Christopher Grossert, and Martin Weitz — Institut für Angewandte Physik der Universität Bonn, Wegelerstr. 8, 53115 Bonn, Germany
Ratchets are devices that are able to generate a directed motion of particles in a fluctuating environment without any gradients or net forces. In order to observe the ratchet effect, one has to break the spatiotemporal symmetry of the system . We have experimentally realized a Hamiltonian Quantum Ratchet . Directed motion of a 87Rb Bose-Einstein condensate is achieved by asymmetrically modulating the ampltitude of the ratchet potential.
Furthermore Absolute Negative Mobility (ANM), a counterintuitive motion against an external bias force, is presented. This effect has also been investigated with ac-driven systems in general.
 S. Denisov et al., Phys. Rev. A 75, 063424 (2007)
 T. Salger et al., Science 326, 1241 (2009)