Imaging Spatially Varying Magnetic Order in Proximity Induced Magnetic Topological Insulator

ORAL

Abstract

Broken time-reversal symmetry on the surface states of a three dimensional topological insulator, such as Bi$_2$Se$_3$, results in quantized anomalous Hall conductance and is predicted to exhibit topological magneto-electric effects. We plan investigate how Dirac fermions interact with magnetism by imaging the magnetization of a topological insulator (Bi$_2$Se$_3$) sandwiched between two ferromagnetic insulator layers (EuS) with a scanning SQUID microscope. Cooling in an in-plane field leads to a magnetization that varies spatially on a micron scale, with 6-fold rotational symmetry. Understanding the origin of this magnetism may shed light on the exchange interaction and electronic properties of topological insulators.

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Authors

  • Aaron J. Rosenberg

    • Stanford University

  • Ferhat Katmis

    • MIT

  • Yihua H. Wang

    • Stanford University

  • John R. Kirtley

    • Stanford University

  • Jagadeesh S. Moodera

    • MIT

  • Kathryn A. Moler

    • Stanford Institute for Materials and Energy Sciences, SLAC National Laboratories