Peculiar interference pattern of Josephson junctions involving periodic ferromagnet-normal metal structure

Abstract

We report the observation of an oscillatory behavior of the critical current versus magnetic field dependence in Nb/(Al/Py)5/Al/AlOx/(Al/Py)6/Al/Nb Josephson tunnel junctions at 4.2 K. The oscillations resemble those that occur in superconducting quantum interference devices. Since the oscillations occur in the junctions without any superconducting loop, and therefore are suitable for sub-micrometer miniaturization, we believe they are promising for the development of a new generation of field-sensitive nanodevices.