This individual investigator award will support time-resolved transport and imaging studies in superconductors in order to elucidate the mechanisms that govern their response to applied fields and currents. The emphasis will be on the onset of motion in vortex lattices in type II superconductors, the vortex lattice's evolution and reorganization from a static structure into a moving steady state and how these properties depend on driving force, quenched disorder, temperature and boundaries. In addition experiments are proposed to identify characteristic signatures predicted for the moving phases including the transverse critical current, and the generation of a narrow band noise. The measurements will be carried out with a novel microscope, constructed in the PI's laboratory, which incorporates time-resolved transport, STM and Hall probe capabilities. The impact of this research is expected to extend to the physics of other moving structures including charge density wave systems, magnetic bubbles, and Wigner crystals. Work on this project will be carried out with the active participation of students at the graduate and undergraduate level and of post doctoral fellows. These young scientists will receive training in cutting edge research and in the use of state of the art equipment that will prepare them for filling demanding technical and research positions in industry and academia. %%%%
Vortices in superconductors are tiny whirlpools of current swirling around microscopic threads containing a quantum of magnetic flux. It is because of vortices that superconductors are able to preserve their remarkable properties when carrying large amounts of current and it is thanks to vortices that superconductors hold the promise of revolutionizing many aspects of our daily lives including transportation, communications, medical diagnosis, energy storage and transmission lines. As long as vortices are pinned in place superconductivity is maintained, but once they start moving the superconductor transforms into a rather poor metal. The primary object of this research is to elucidate the mechanisms that lead to the onset of vortex motion and to study the patterns and dynamic phases that emerge once the motion is established. This research project will employ a variety of novel techniques developed in the PI's laboratory to probe the onset of motion of vortices in superconductors, their evolution and reorganization from a static structure into a moving state. The impact of this research is expected to extend to the physics of other moving structures including charge density wave systems, magnetic bubbles, and electron crystals. Work on this project will be carried out with the active participation of students at the graduate and undergraduate level and of post doctoral fellows. These young scientists will receive training in cutting edge research and in the use of state of the art equipment that will prepare them for filling demanding technical and research positions in industry and academia.
