---
_id: '10616'
abstract:
- lang: eng
  text: Electrons in moiré flat band systems can spontaneously break time-reversal
    symmetry, giving rise to a quantized anomalous Hall effect. In this study, we
    use a superconducting quantum interference device to image stray magnetic fields
    in twisted bilayer graphene aligned to hexagonal boron nitride. We find a magnetization
    of several Bohr magnetons per charge carrier, demonstrating that the magnetism
    is primarily orbital in nature. Our measurements reveal a large change in the
    magnetization as the chemical potential is swept across the quantum anomalous
    Hall gap, consistent with the expected contribution of chiral edge states to the
    magnetization of an orbital Chern insulator. Mapping the spatial evolution of
    field-driven magnetic reversal, we find a series of reproducible micrometer-scale
    domains pinned to structural disorder.
acknowledgement: 'We thank A. H. Macdonald, J. Zhu, M. Zaletel, and D. Xiao for discussions
  of the results and E. Lachman for comments on the manuscript. Funding: The work
  was primarily funded by the US Department of Energy under DE-SC0020043, with additional
  support for instrumentation development supported by the Army Research Office under
  grant W911NF-16-1-0361. K.W. and T.T. acknowledge support from the Elemental Strategy
  Initiative conducted by MEXT, Japan, grant JPMXP0112101001; JSPS KAKENHI grant JP20H00354
  and CREST grant JPMJCR15F3, JST. C.L.T. acknowledges support from the Hertz Foundation
  and from the National Science Foundation Graduate Research Fellowship Program under
  grant 1650114. This project is funded in part by the Gordon and Betty Moore Foundation’s
  EPiQS Initiative, grant GBMF9471 to A.F.Y.'
article_processing_charge: No
article_type: original
arxiv: 1
author:
- first_name: C. L.
  full_name: Tschirhart, C. L.
  last_name: Tschirhart
- first_name: M.
  full_name: Serlin, M.
  last_name: Serlin
- first_name: Hryhoriy
  full_name: Polshyn, Hryhoriy
  id: edfc7cb1-526e-11ec-b05a-e6ecc27e4e48
  last_name: Polshyn
  orcid: 0000-0001-8223-8896
- first_name: A.
  full_name: Shragai, A.
  last_name: Shragai
- first_name: Z.
  full_name: Xia, Z.
  last_name: Xia
- first_name: J.
  full_name: Zhu, J.
  last_name: Zhu
- first_name: Y.
  full_name: Zhang, Y.
  last_name: Zhang
- first_name: K.
  full_name: Watanabe, K.
  last_name: Watanabe
- first_name: T.
  full_name: Taniguchi, T.
  last_name: Taniguchi
- first_name: M. E.
  full_name: Huber, M. E.
  last_name: Huber
- first_name: A. F.
  full_name: Young, A. F.
  last_name: Young
citation:
  ama: Tschirhart CL, Serlin M, Polshyn H, et al. Imaging orbital ferromagnetism in
    a moiré Chern insulator. <i>Science</i>. 2021;372(6548):1323-1327. doi:<a href="https://doi.org/10.1126/science.abd3190">10.1126/science.abd3190</a>
  apa: Tschirhart, C. L., Serlin, M., Polshyn, H., Shragai, A., Xia, Z., Zhu, J.,
    … Young, A. F. (2021). Imaging orbital ferromagnetism in a moiré Chern insulator.
    <i>Science</i>. American Association for the Advancement of Science. <a href="https://doi.org/10.1126/science.abd3190">https://doi.org/10.1126/science.abd3190</a>
  chicago: Tschirhart, C. L., M. Serlin, Hryhoriy Polshyn, A. Shragai, Z. Xia, J.
    Zhu, Y. Zhang, et al. “Imaging Orbital Ferromagnetism in a Moiré Chern Insulator.”
    <i>Science</i>. American Association for the Advancement of Science, 2021. <a
    href="https://doi.org/10.1126/science.abd3190">https://doi.org/10.1126/science.abd3190</a>.
  ieee: C. L. Tschirhart <i>et al.</i>, “Imaging orbital ferromagnetism in a moiré
    Chern insulator,” <i>Science</i>, vol. 372, no. 6548. American Association for
    the Advancement of Science, pp. 1323–1327, 2021.
  ista: Tschirhart CL, Serlin M, Polshyn H, Shragai A, Xia Z, Zhu J, Zhang Y, Watanabe
    K, Taniguchi T, Huber ME, Young AF. 2021. Imaging orbital ferromagnetism in a
    moiré Chern insulator. Science. 372(6548), 1323–1327.
  mla: Tschirhart, C. L., et al. “Imaging Orbital Ferromagnetism in a Moiré Chern
    Insulator.” <i>Science</i>, vol. 372, no. 6548, American Association for the Advancement
    of Science, 2021, pp. 1323–27, doi:<a href="https://doi.org/10.1126/science.abd3190">10.1126/science.abd3190</a>.
  short: C.L. Tschirhart, M. Serlin, H. Polshyn, A. Shragai, Z. Xia, J. Zhu, Y. Zhang,
    K. Watanabe, T. Taniguchi, M.E. Huber, A.F. Young, Science 372 (2021) 1323–1327.
date_created: 2022-01-13T12:17:45Z
date_published: 2021-05-27T00:00:00Z
date_updated: 2022-01-13T14:11:36Z
day: '27'
doi: 10.1126/science.abd3190
extern: '1'
external_id:
  arxiv:
  - '2006.08053'
  pmid:
  - '34045322'
fulldoi: https://doi.org/10.1126/science.abd3190
intvolume: '       372'
issue: '6548'
keyword:
- multidisciplinary
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://arxiv.org/abs/2006.08053
month: '05'
oa: 1
oa_version: Preprint
page: 1323-1327
pmid: 1
publication: Science
publication_identifier:
  eissn:
  - 1095-9203
  issn:
  - 0036-8075
publication_status: published
publisher: American Association for the Advancement of Science
quality_controlled: '1'
scopus_import: '1'
status: public
title: Imaging orbital ferromagnetism in a moiré Chern insulator
type: journal_article
user_id: 8b945eb4-e2f2-11eb-945a-df72226e66a9
volume: 372
year: '2021'
...