Vortex-state electrodynamics in superconducting thin films studied by infrared spectroscopy

POSTER

Abstract

In a type-II superconductor, a magnetic field above the lower critical field creates vortices and dramatically changes the superconductor's electrodynamic response. Such changes have been observed in thin film samples by our infrared magneto-spectroscopy experiments with field normal to the film surface. The complex optical conductivity was extracted, and was compared to existing models for the effective electrodynamic response of the vortex state. We found a good agreement between our optical data and a calculation using Maxwell Garnett theory, which treats the mixed state as having normal-metal disks (representing the vortex cores) surrounded by superconductor. Our data also show the effect of magnetic-field-induced pair breaking on the superconducting fraction outside of the vortices.

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Authors

  • Xiaoxiang Xi

    Department of Physics, University of Florida

  • D.B. Tanner

    Department of Physics, University of Florida, University of Florida, Department of Physics, University of Florida, Gainesville, Florida 32611, USA, Department of Physics, University of Florida, Gainesville, Florida 32611

  • G.L. Carr

    Photon Sciences, Brookhaven National Laboratory, Brookhaven National Laboratory, National Synchrotron Light Source, Brookhaven National Laboratory

  • J.-H. Park

    National High Magnetic Field Laboratory, Florida State University

  • D. Graf

    National High Magnetic Field Laboratory, Florida State University