Journal article

High bias anomaly in YBa₂Cu₃O7−x/LaMnO₃₊/YBa₂Cu₃O7−x superconductor/ferromagnetic insulator/superconductor junctions: Evidence for a long-range superconducting proximity effect through the conduction band of a ferromagnetic insulator

  • Golod, T. Department of Physics, Stockholm University, Sweden
  • Rydh, A. Department of Physics, Stockholm University, Sweden
  • Krasnov, V. M. Department of Physics, Stockholm University, Sweden
  • Marozau, Ivan University of Fribourg, Department of Physics and Fribourg Centre for Nanomaterials, Switzerland
  • Uribe-Laverde, Miguel Angel University of Fribourg, Department of Physics and Fribourg Centre for Nanomaterials, Switzerland
  • Satapathy, Dillip Kumar University of Fribourg, Department of Physics and Fribourg Centre for Nanomaterials, Switzerland
  • Wagner, Th. University of Fribourg, Department of Physics and Fribourg Centre for Nanomaterials, Switzerland
  • Bernhard, Christian University of Fribourg, Department of Physics and Fribourg Centre for Nanomaterials, Switzerland
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    30.04.2013
Published in:
  • Physical Review B. - 2013, vol. 87, no. 13, p. 134520
English We study the perpendicular transport characteristics of small superconductor/ferromagnetic insulator/superconductor (YBa₂Cu₃O7−x/LaMnO₃₊/YBa₂Cu₃O7−x) tunnel junctions. At a large bias voltage V∼1 V we observe a steplike onset of excess current that occurs below the superconducting transition temperature Tc and is easily suppressed by a magnetic field. The phenomenon is attributed to a different type of the superconducting proximity effect of nonequilibrium electrons injected into the conduction band of the ferromagnetic insulator via a Fowler-Nordheim tunneling process. The occurrence of a strongly nonequilibrium population is confirmed by the detection of photon emission at large bias voltage. Since the conduction band in our ferromagnetic insulator is strongly spin polarized, the long range (20 nm) of the observed proximity effect provides evidence for an unconventional spin-triplet superconducting state.
Faculty
Faculté des sciences et de médecine
Department
Département de Physique
Language
  • English
Classification
Physics
License
License undefined
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Persistent URL
https://folia.unifr.ch/unifr/documents/303036
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