Measurements of the quasiparticle recombination process in a type II superconductor with field-suppressed energy gap

ORAL

Abstract

Our pump-probe studies of excess quasiparticle relaxation in the type II superconductor NbTiN show a relaxation rate proportional to the excess quasiparticle number density, as expected for bimolecular recombination driven by a large excess quasiparticle population. Application of a magnetic field parallel to the sample surface is found to slow significantly the quasiparticle recombination process. We compare our results with a model of recombination that considers two candidate magnetic field effects: quasiparticle spin polarization (paramagnetism) and finite pair lifetime effects, with the latter appearing to be the more important.

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Authors

  • Xiaoxiang Xi

    Department of Physics, University of Florida, Department of Physics, Univ. of Florida, University of Florida

  • J. Hwang

    Department of Physics, Pusan National University, Department of Physics, Pusan National Univ., Pusan National University

  • H. Zhang

    Department of Physics, University at Buffalo

  • D.H. Reitze

    Department of Physics, University of Florida, Department of Physics, Univ. of Florida

  • C.J. Stanton

    University of Florida, Department of Physics, University of Florida

  • David Tanner

    University of Florida Physics Department, Physics Department, University of Florida, University of Florida, Department of Physics, University of Florida, Department of Physics, Univ. of Florida, Department of physics, University of Florida

  • G.L. Carr

    Brookhaven National Laboratory, NSLS, Brookhaven National Laboratory, NSLS - Brookhaven National Lab