Ratchet effect in dc SQUIDs
II.Physikalisches Institut, Universität zu Köln - D-50937 Köln,
2 Institut für Schicht- und Ionentechnik, Forschungszentrum Jülich D-52425 Jülich, Germany
Corresponding author: firstname.lastname@example.org
Accepted: 28 June 2000
We analyzed voltage rectification for dc SQUIDs biased with ac current with zero mean value. We demonstrate that the reflection symmetry in the 2-dimensional SQUID potential is broken by an applied flux and with appropriate asymmetries in the dc SQUID. Depending on the type of asymmetry, we obtain a rocking or a simultaneously rocking and flashing ratchet, the latter showing multiple sign reversals in the mean voltage with increasing amplitude of the ac current. Our experimental results are in agreement with numerical solutions of the Langevin equations for the asymmetric dc SQUID.
PACS: 05.60.-k – Transport processes / 85.25.Dq – Superconducting quantum interference devices (SQUIDs) / 05.40.-a – Fluctuation phenomena, random processes, noise, and Brownian motion
© EDP Sciences, 2000