Exchange-biased Quantum Anormalous Hall Effect in Magnetic Topological Insulator and Antiferromagnetic Insulator Heterostructure

ORAL

Abstract

The integration of topological and (anti)ferromagnetic layers has attracted wide interest, to introduce ferromagnetism into nonmagnetic topological insulators (TIs) or to enhance the Curie temperature of magnetically doped topological insulators (MTIs). In addition, the exchange coupling between the layers provides an additional degree of freedom through which the topological surface states can be manipulated. Here, we report on exchange coupling between the quantum anomalous Hall (QAH) state of MTI and an antiferromagnetic insulator with a net parasitic magnetization, Al-doped Cr2O3. Polarized neutron reflectometry (PNR) measurements reveal a strong exchange coupling between the two magnetic layers pinning the moments at the interface to point out-of-plane, which leads to the observation of an exchange-biased QAH on the transport signal for the first time.

*We acknowledge the funding support from Army Research Office Multidisciplinary University Research Initiative (MURI) program under contract W911NF-16-1-0472 and WN911NF-20-2-0166

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Presenters

  • Peng Zhang

    • University of California, Los Angeles

Authors

  • Peng Zhang

    • University of California, Los Angeles

  • Purnima P Balakrishnan

    • National Institute of Standards and Tech
    • National Institute of Standards and Technology

  • Chris Eckberg

    • University of Maryland, College Park
    • University of California, Los Angeles
    • US Army Research Laboratory

  • Peng Deng

    • University of California, Los Angeles

  • Tomohiro Nozaki

    • Tohoku University

  • Alexander Grutter

    • National Institute of Standards and Technology
    • National Institute of Standards and Tech

  • Kang-Lung Wang

    • University of California, Los Angeles