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.

*Supported by the US DOE through contracts DE-FG02-02ER45984 at UF and DE-AC02-98CH10886 at the NSLS. Access to the high-field magnet courtesy of J.J. Tu (CCNY).

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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