date:RIKEN, Inst Phys & Chem Res, Frontier Res Syst, Wako, Saitama 3510198, Japan; Univ Camerino, Ist Nazl Fis Mat, I-62032 Camerino, Italy; Katholieke Univ Leuven, Vaste Stof Fys Magnetisme Lab, B-3001 Louvain, Belgium; Univ Michigan, CSCS, Ctr Theoret Phys, Dept Phys, Ann Arbor, MI 48109 USA
We study the transport of vortices in superconductors with regular arrays of asymmetric pinning wells when applying an alternating electrical current. We show that this system can induce a net rectifying or diode effect for the vortex motion, including collective stepmotor-type dynamics, where many vortices move forward a controlled and exact number of pin-lattice-spacings at each cycle of the AC driving force. This results in a remarkable net DC response with striking sawtooth-type oscillations. This system provides an experimentally realizable stepmotor of quanta and a precise control of the motion of vortices. (C) 2003 Elsevier Science B.V. All rights reserved.