Emergent vortices at a ferromagnetic superconducting oxide interface
Petrović, A P
Paudel, T R
Barnes, C H W
Tsymbal, E Y
Date of Issue2014
School of Physical and Mathematical Sciences
Understanding the cohabitation arrangements of ferromagnetism and superconductivity at the LaAlO3/SrTiO3 interface remains an open challenge. Probing this coexistence with sub-Kelvin magnetotransport experiments, we demonstrate that a hysteretic in-plane magnetoresistance develops below the superconducting transition for H < 0.15 T, independently of the carrier density or oxygen annealing. This hysteresis is argued to arise from vortex depinning within a thin (< 20 nm) superconducting layer, mediated by discrete ferromagnetic dipoles located solely above the layer. The pinning strength may be modified by varying the superconducting channel thickness via electric field-effect doping. No evidence is found for bulk magnetism or finite-momentum pairing, and we conclude that ferromagnetism is strictly confined to the interface, where it competes with superconductivity. Our work indicates that oxide interfaces are ideal candidate materials for the growth and analysis of nanoscale superconductor/ferromagnet hybrids.
DRNTU::Science::Physics::Electricity and magnetism
New journal of physics
© 2014 IOP Publishing Ltd and Deutsche Physikalische Gesellschaft. This paper was published in New Journal of Physics and is made available as an electronic reprint (preprint) with permission of IOP Publishing Ltd. The paper can be found at the following official DOI: [http://dx.doi.org/10.1088/1367-2630/16/10/103012]. One print or electronic copy may be made for personal use only. Systematic or multiple reproduction, distribution to multiple locations via electronic or other means, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper is prohibited and is subject to penalties under law.