Bistable Abrikosov vortex diode made of a Py–Nb ferromagnet-superconductor bilayer structure

Abstract

We report magnetotransport measurements on Py/Nb bilayers patterned in a Hall strip geometry, with Permalloy allowing a weak stripe domain regime. After application of a weak magnetic field in the plane of the bilayer perpendicular to the transport current, the strip behaves as a bistable superconducting diode and a nonvolatile superconducting valve as well. The observed behavior can be accounted for by the stray fields at the edges of the strip that modulate the distribution of the stray fields from the stripe domains in the ferromagnetic layer, generating an asymmetric and bistable magnetic forces background for the Abrikosov vortices moving in the superconducting layer.