Ghost critical field and weak localization phenomena in superconducting Tantalum Nitride films

ORAL

Abstract

We study the appearance of superconducting fluctuations and weak localization effects in a disordered thin film of Tantalum Nitride using magnetotransport measurements. At temperatures above Tc, we observe a large positive magnetoresistance that is 4 orders of magnitude larger than the predicted classical effect. Well above Tc this behavior is consistent with the magnetic field dependence of localization quantum corrections to the conductivity in the presence of strong spin-orbit scattering. Close to Tc and at low magnetic fields the observed magnetoresistance is well described by recent theories that describe both localization and superconducting fluctuations effects. This analysis allows for quantitative study of the inelastic scattering time and the so-called ghost critical field.

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Authors

  • Nicholas Breznay

    Stanford University

  • G.V. Brown

    Department of Physics at CSU, Fresno, Lawrence Livermore National Laboratory, Stanford University, Advanced Light Source, Lawrence Berkeley National Lab, Nanoelectronics Research Institute, Japan Atomic Energy Agency, University of Tokyo, Cornell University, Tokyo Institute of Technology, Suranaree University of Technology, Shandong University, Stanford Synchrotron Radiation Lightsource, UC Davis, CSU Dominguez Hills, Thomas Jefferson National Accelerator Facility, UC Berkeley, ANL, UChicago/ANL, UManitoba, Northwestern U/ANL, LLNL, UCB/LLNL, McGill U, McGill U/ANL, University of Nevada, Reno, Hitachi Global Storage Technology, Advanced Light Source, Stanford Synchrotron Radiation Laboratory, Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Materials Science and Engineering, Stanford University, Radiation Oncology, Stanford University School of Medicine, Missouri University of Science and Technology, International Institute of Physics, University of Missouri, University of Notre Dame du Lac, Department of Physics, California State University, Fresno, California, California State University Long Beach, BNL, IWF Dresden, Department of Physics, University of California, Davis, CA 95616, USA, University of California, Merced, Laboratoire Univers et Particules de Montpellier, IN2P3 (France), SLAC National Accelerator Laboratory/Stanford University/KIPAC, University of Perugia, University of Washington, CEA/Saclay, UNR, UNM, UCSD, RAL, ILE, MIT, LANL, LLE, NRL, SLAC National Accelerator Laboratory, Technische Universitaet Berlin, Max Born Institut, Hiroshima University, Western Michigan University, MPIK