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arXiv · 1306.2038

Emerging Weak Localization Effects on Topological Insulator-Insulating Ferromagnet (Bi_2Se_3-EuS) Interface

Qi I. Yang·Merav Dolev·Li Zhang·Jinfeng Zhao·Alexander D. Fried·Elizabeth Schemm·Min Liu·Alexander Palevski·Ann F. Marshall·Subhash H. Risbud·Aharon Kapitulnik
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Abstract

Thin films of topological insulator Bi_2Se_3 were deposited directly on insulating ferromagnetic EuS. Unusual negative magnetoresistance was observed near the zero field below the Curie temperature (T_C), resembling the weak localization effect; whereas the usual positive magnetoresistance was recovered above T_C. Such negative magnetoresistance was only observed for Bi_2Se_3 layers thinner than t~4nm, when its top and bottom surfaces are coupled. These results provide evidence for a proximity effect between a topological insulator and an insulating ferromagnet, laying the foundation for future realization of the half-integer quantized anomalous Hall effect in three-dimensional topological insulators.

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Qi I. Yang, Merav Dolev, Li Zhang, Jinfeng Zhao, Alexander D. Fried, Elizabeth Schemm, Min Liu, Alexander Palevski, Ann F. Marshall, Subhash H. Risbud, Aharon Kapitulnik. 2013-06-09. Emerging Weak Localization Effects on Topological Insulator-Insulating Ferromagnet (Bi_2Se_3-EuS) Interface. https://doi.org/10.1103/physrevb.88.081407

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