Guided vortex motion in a ferromagnet-superconductor bilayer

Abstract

Vortex motion in ferromagnetic-superconducting bilayers constituted by thin YBa$_2$Cu$_3$O$_{7-\delta}$ film deposited on the top of thin manganite La$_{0.67}$Sr$_{0.33}$MnO$_3$ film has been investigated. Both films were deposited on uniformly twinned single-crystalline substrates and patterned into strips directed at different angles to the twin lines pattern. These conditions lead to the guided vortex motion at different angles to the periodic pinning potential. It has been established that critical current and flux flow resistance in such an anisotropic pinning landscape-scale follow the elliptic dependence on the angle of the direction of the strip. For vortex flow at the directions close to the perpendicular to magnetic domain walls, signatures of the coherence in the vortex motion have been observed.