Magnetic field dependence of quasiparticle recombination times in superconducting NbTiN at low laser fluence

ORAL

Abstract

We use a pump-probe technique to study the temperature and field dependent quasiparticle recombination process in superconducting Nb$_{0.5}$Ti$_{0.5}$N in the low laser fluence regime. The sample was excited by a picosecond near-infrared Ti:Sapphire laser pulses and probed with subnanosecond infrared synchrotron pulses at the National Synchrotron Light Source, Brookhaven National Laboratory. Time-resolved photoinduced transmission data were obtained as a function of temperature (2.2-10 K) and magnetic field (0-10 T), from which we calculated the quasiparticle effective lifetime. Both temperature and field dependence were observed, with the effective lifetime increasing as the field became stronger. A model of this phenomenon will be discussed.

*Research supported by the DOE through grant DE-FG02-02ER45984 at Florida and contract DE-AC02-98CH10886 at BNL.

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Authors

  • X. Xi

    • University of Florida
    • Department of Physics, University of Florida

  • J. Hwang

    • University of Florida
    • Department of Physics, University of Florida

  • Dave H. Reitze

    • University of Florida
    • Department of Physics, University of Florida
    • Physics Dept. University of Florida

  • C.J. Stanton

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

  • David B. Tanner

    • University of Florida
    • Department of Physics, University of Florida
    • UFL, phys dept

  • G.L. Carr

    • Brookhaven National Laboratory
    • NSLS, Brookhaven National Laboratory
    • NSLS, Brookhaven National Laboratory, Upton, NY
    • NSLS, Brookhaven National Lab