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Title: Intrinsic quantized anomalous Hall effect in a moiré heterostructure

Abstract

The quantum anomalous Hall (QAH) effect combines topology and magnetism to produce precisely quantized Hall resistance at zero magnetic field. We report the observation of a QAH effect in twisted bilayer graphene aligned to hexagonal boron nitride. The effect is driven by intrinsic strong interactions, which polarize the electrons into a single spin- and valley-resolved moiré miniband with Chern number C = 1. In contrast to magnetically doped systems, the measured transport energy gap is larger than the Curie temperature for magnetic ordering, and quantization to within 0.1% of the von Klitzing constant persists to temperatures of several kelvin at zero magnetic field. Electrical currents as small as 1 nanoampere controllably switch the magnetic order between states of opposite polarization, forming an electrically rewritable magnetic memory.

Authors:
 [1]; ORCiD logo [1]; ORCiD logo [1]; ORCiD logo [1];  [1]; ORCiD logo [2];  [2]; ORCiD logo [3]; ORCiD logo [1]
  1. Department of Physics, University of California, Santa Barbara, Santa Barbara, CA 93106, USA.
  2. National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan.
  3. Kavli Institute for Theoretical Physics, University of California, Santa Barbara, Santa Barbara, CA 93106, USA.
Publication Date:
Sponsoring Org.:
USDOE
OSTI Identifier:
1600874
Grant/Contract Number:  
[FG02-08ER46524]
Resource Type:
Published Article
Journal Name:
Science
Additional Journal Information:
[Journal Name: Science Journal Volume: 367 Journal Issue: 6480]; Journal ID: ISSN 0036-8075
Publisher:
American Association for the Advancement of Science (AAAS)
Country of Publication:
United States
Language:
English

Citation Formats

Serlin, M., Tschirhart, C. L., Polshyn, H., Zhang, Y., Zhu, J., Watanabe, K., Taniguchi, T., Balents, L., and Young, A. F. Intrinsic quantized anomalous Hall effect in a moiré heterostructure. United States: N. p., 2019. Web. doi:10.1126/science.aay5533.
Serlin, M., Tschirhart, C. L., Polshyn, H., Zhang, Y., Zhu, J., Watanabe, K., Taniguchi, T., Balents, L., & Young, A. F. Intrinsic quantized anomalous Hall effect in a moiré heterostructure. United States. doi:10.1126/science.aay5533.
Serlin, M., Tschirhart, C. L., Polshyn, H., Zhang, Y., Zhu, J., Watanabe, K., Taniguchi, T., Balents, L., and Young, A. F. Thu . "Intrinsic quantized anomalous Hall effect in a moiré heterostructure". United States. doi:10.1126/science.aay5533.
@article{osti_1600874,
title = {Intrinsic quantized anomalous Hall effect in a moiré heterostructure},
author = {Serlin, M. and Tschirhart, C. L. and Polshyn, H. and Zhang, Y. and Zhu, J. and Watanabe, K. and Taniguchi, T. and Balents, L. and Young, A. F.},
abstractNote = {The quantum anomalous Hall (QAH) effect combines topology and magnetism to produce precisely quantized Hall resistance at zero magnetic field. We report the observation of a QAH effect in twisted bilayer graphene aligned to hexagonal boron nitride. The effect is driven by intrinsic strong interactions, which polarize the electrons into a single spin- and valley-resolved moiré miniband with Chern number C = 1. In contrast to magnetically doped systems, the measured transport energy gap is larger than the Curie temperature for magnetic ordering, and quantization to within 0.1% of the von Klitzing constant persists to temperatures of several kelvin at zero magnetic field. Electrical currents as small as 1 nanoampere controllably switch the magnetic order between states of opposite polarization, forming an electrically rewritable magnetic memory.},
doi = {10.1126/science.aay5533},
journal = {Science},
number = [6480],
volume = [367],
place = {United States},
year = {2019},
month = {12}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record
DOI: 10.1126/science.aay5533

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