Liu, X, Farahi, G, Chiu, C-L et al. (5 more authors) (2022) Visualizing broken symmetry and topological defects in a quantum Hall ferromagnet. Science, 375 (6578). pp. 321-326. ISSN 0036-8075
Abstract
The interaction between electrons in graphene under high magnetic fields drives the formation of a rich set of quantum Hall ferromagnetic (QHFM) phases with broken spin or valley symmetry. Visualizing atomic-scale electronic wave functions with scanning tunneling spectroscopy (STS), we resolved microscopic signatures of valley ordering in QHFM phases and spectral features of fractional quantum Hall phases of graphene. At charge neutrality, we observed a field-tuned continuous quantum phase transition from a valley-polarized state to an intervalley coherent state, with a Kekulé distortion of its electronic density. Mapping the valley texture extracted from STS measurements of the Kekulé phase, we could visualize valley skyrmion excitations localized near charged defects. Our techniques can be applied to examine valley-ordered phases and their topological excitations in a wide range of materials.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2022 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works. This is an author produced version of an article published in Science. Uploaded in accordance with the publisher's self-archiving policy. |
Keywords: | cond-mat.mes-hall; cond-mat.mes-hall; cond-mat.str-el |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Physics and Astronomy (Leeds) > Theoretical Physics (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 06 Dec 2021 11:33 |
Last Modified: | 27 Jan 2022 16:39 |
Status: | Published |
Publisher: | American Association for the Advancement of Science |
Identification Number: | 10.1126/science.abm3770 |
Related URLs: | |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:181167 |