Predicted field-dependent increase of critical currents in asymmetric superconducting nanocircuits

John R. Clem, Yasunori Mawatari, G. R. Berdiyorov, F. M. Peeters

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36 Citations (Scopus)

Abstract

The critical current of a thin superconducting strip of width W much larger than the Ginzburg-Landau coherence length ξ but much smaller than the Pearl length Λ=2λ2/d is maximized when the strip is straight with defect-free edges. When a perpendicular magnetic field is applied to a long straight strip, the critical current initially decreases linearly with H but then decreases more slowly with H when vortices or antivortices are forced into the strip. However, in a superconducting strip containing sharp 90 or 180 turns, the zero-field critical current at H=0 is reduced because vortices or antivortices are preferentially nucleated at the inner corners of the turns, where current crowding occurs. Using both analytic London-model calculations and time-dependent Ginzburg-Landau simulations, we predict that in such asymmetric strips the resulting critical current can be increased by applying a perpendicular magnetic field that induces a current-density contribution opposing the applied current density at the inner corners. This effect should apply to all turns that bend in the same direction.

Original languageEnglish
Article number144511
JournalPhysical Review B - Condensed Matter and Materials Physics
Volume85
Issue number14
DOIs
Publication statusPublished - 10 Apr 2012

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ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics

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