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arXiv · 1311.2323

The Vortex Signature of Discrete Ferromagnetic Dipoles at the LaAlO$_3$/SrTiO$_3$ Interface

A. P. Petrović·A. Paré·T. R. Paudel·K. Lee·S. Holmes·C. H. W. Barnes·A. David·T. Wu·E. Y. Tsymbal·C. Panagopoulos
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Abstract

A hysteretic in-plane magnetoresistance develops below the superconducting transition of LaAlO$_3$/SrTiO$_3$ interfaces for $\left|H_{/\!/}\right|<$ 0.15 T, independently of the carrier density or oxygen annealing. We show that this hysteresis arises from vortex depinning within a thin superconducting layer, in which the vortices are created by discrete ferromagnetic dipoles located solely above the layer. We find no evidence for finite-momentum pairing or bulk magnetism and hence conclude that ferromagnetism is strictly confined to the interface, where it competes with superconductivity.

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A. P. Petrović, A. Paré, T. R. Paudel, K. Lee, S. Holmes, C. H. W. Barnes, A. David, T. Wu, E. Y. Tsymbal, C. Panagopoulos. 2013-11-11. The Vortex Signature of Discrete Ferromagnetic Dipoles at the LaAlO$_3$/SrTiO$_3$ Interface. https://doi.org/10.1088/1367-2630%2F16%2F10%2F103012

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