Two-Stage Proximity-Induced Gap-Opening in Topological Insulator–Insulating Ferromagnet (Bi<sub>x</sub>Sb<sub>1-x</sub>)<sub>2</sub>Te<sub>3</sub>–EuS Bilayers

ORAL

Abstract

To further investigate the interplay between ferromagnetism and topological insulators, the low-carrier topological insulator (BixSb1-x)2Te3 thin films were deposited on the insulating ferromagnet EuS (100) in situ. AC susceptibility indicates magnetic anomalies at T ≈ 30 K and T ≈ 60 K, above the Curie temperature TC ≈ 15 K. When the Fermi level is close to the Dirac point and the surface state dominates the electric conduction, sharp increases in resistance were observed at the same temperature range. Together with the positive-negative magnetoresistance crossover at the Curie temperature, a two-stage gap-opening process due to magnetic proximity is proposed.

*Part of the experiments was performed at the Stanford Nano Shared Facilities (SNSF), supported by the National Science Foundation under award ECCS-1542152. This work is supported by DARPA, MesoDynamic Architecture Program (MESO) through the contract number N66001-11-1-4105, by FENA, and by a seed grant f

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Presenters

  • Qi Yang

    • Physics, Stanford Univ

Authors

  • Qi Yang

    • Physics, Stanford Univ

  • Aharon Kapitulnik

    • Stanford University
    • Stanford Univ
    • Physics, Stanford Univ