Berlin 2012 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
DY: Fachverband Dynamik und Statistische Physik
DY 25: Brownian Motion and Transport
DY 25.8: Vortrag
Donnerstag, 29. März 2012, 11:45–12:00, MA 004
Ratchet (re)loaded — •Edward Goldobin1, Martin Knufinke1, Dieter Koelle1, Reinhold Kleiner1, Konstantin Il’in2, and Michael Siegel2 — 1Physikalisches Institut and Center for Collective Quantum Phenomena in LISA+, University of Tübingen, 72076 Tübingen, Germany — 2Institut für Mikro- und Nanoelektronische Systeme, Karlsruhe Institute of Technology, 76187 Karlsruhe, Germany
We investigate experimentally a deterministic underdamped Josephson vortex ratchet – a fluxon-particle moving along a Josephson junction in an asymmetric periodic potential. By applying a sinusoidal driving current one can compel the vortex to move in a certain direction, producing an average dc voltage across the junction. Being in such a rectification regime we also load the ratchet, i.e., apply an additional dc bias current Idc (counterforce) which tilts the potential so that the fluxon climbs uphill due to the ratchet effect. The value of the bias current at which the fluxon stops climbing up defines the strength of the ratchet effect and is determined experimentally. This allows us to estimate the loading capability of the ratchet, the output power and efficiency. For the quasi-static regime we present a simple model which delivers simple analytic expressions for the above mentioned figures of merit. [1]
[1] M. Knufinke et al., arXiv:1109.6507