Phonon Escape Time Deduced from the Time of Nucleation of Hot Spots in Superconducting Niobium Filaments

K. Harrabi, F. Oktasendra, K. Gasmi, Golibjon Berdiyorov, A. Mekki, J. P. Maneval

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We have observed the voltage response of superconducting niobium strips to overcritical (I > Ic) step pulses of electrical current. The resistive response appears after a certain delay time td function of the temperature and of the ratio I/Ic(T), which can be analyzed through a time-dependent Ginzburg-Landau equation, along the method introduced by Tinkham. The experimental data can be fitted by using an effective gap relaxation time of a few nanoseconds, independently of the sample widths and of the temperature. Assuming proportionality to sample thickness, this indicates a phonon escape time of about 8 ps per nanometer of thickness for a Nb film dc sputtered on polished crystalline Al2O3.

Original languageEnglish
Article number7399353
JournalIEEE Transactions on Applied Superconductivity
Issue number3
Publication statusPublished - 15 Apr 2016



  • Critical current density
  • non-equilibrium superconductivity
  • superconducting thin film

ASJC Scopus subject areas

  • Electrical and Electronic Engineering
  • Condensed Matter Physics
  • Electronic, Optical and Magnetic Materials

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