# Ferromagnetism and topology of the higher flat band in a fractional Chern insulator https://mdr.nims.go.jp/datasets/6b588bfa-081e-4365-8330-abb7295cc45f ## File - [2025A01020G_AcceptedVersion_MDR.pdf](https://mdr.nims.go.jp/filesets/5d4c33bd-b14e-4c37-b593-8a8c34c44f74/download) ([Detail](https://mdr.nims.go.jp/filesets/5d4c33bd-b14e-4c37-b593-8a8c34c44f74.md)) ## Id 6b588bfa-081e-4365-8330-abb7295cc45f ## Local identifier ## Visibility open_to_public ## State published ## Created at 2026-07-01T07:53:22.389727Z ## Updated at 2026-07-03T06:15:10.556148Z ## Published at 2026-07-03T07:29:22.503562Z ## Doi ## First published url https://doi.org/10.1038/s41567-025-02804-0 ## Date published 2025-03-20 ## Recorded date published 2025-4 ## Resource type journal_article ## Manuscript type accepted_manuscript ## Collection ## Title - title: Ferromagnetism and topology of the higher flat band in a fractional Chern insulator title_type: original lang: en ## Description - description: The recent observation of the fractional quantum anomalous Hall effect in moiré fractional Chern insulators provides an opportunity to investigate zero magnetic field anyons. One approach for potentially realizing non-abelian anyons is to engineer higher flat Chern bands that mimic higher Landau levels. We investigate the interaction, topology and ferromagnetism of the second moiré miniband in twisted MoTe2 bilayers. At half-filling of the second miniband, we observed spontaneous ferromagnetism and an incipient Chern insulator state. The Chern numbers of the top two moiré flat bands exhibited opposite signs for twist angles above 3.1° but had the same sign near 2.6°, consistent with theoretical predictions. In the 2.6° device, increasing the magnetic field induced a topological phase transition due to band-crossing between opposite valleys, resulting in an emergent state with Chern number C = −2. Additionally, an insulating state at half-filling of the second valley-polarized band indicates that a charge-ordered state is favoured over the fractional Chern insulator state. These findings lay a foundation for understanding the higher flat Chern bands, which are crucial for the discovery of non-abelian fractional Chern insulators. description_type: abstract lang: en ## Creator - name: Heonjoon Park role: author - name: Jiaqi Cai role: author - name: Eric Anderson role: author - name: Xiao-Wei Zhang role: author - name: Xiaoyu Liu role: author - name: William Holtzmann role: author - name: Weijie Li role: author - name: Chong Wang role: author - name: Chaowei Hu role: author - name: Yuzhou Zhao role: author - name: Takashi Taniguchi role: author orcid: https://orcid.org/0000-0002-1467-3105 organization: National Institute for Materials Science - name: Kenji Watanabe role: author orcid: https://orcid.org/0000-0003-3701-8119 organization: National Institute for Materials Science - name: Jihui Yang role: author - name: David Cobden role: author - name: Jiun-haw Chu role: author - name: Nicolas Regnault role: author - name: B. Andrei Bernevig role: author - name: Liang Fu role: author - name: Ting Cao role: author - name: Di Xiao role: author - name: Xiaodong Xu role: author ## Contact agent ## Publisher organization: Springer Science and Business Media LLC ## Managing organization ## Keyword - subject: Fractional Chern insulators schema: not_defined - subject: Twisted MoTe2 bilayers schema: not_defined - subject: Non-abelian anyons schema: not_defined ## Rights - description: 'This version of the article has been accepted for publication, after peer review (when applicable) and is subject to Springer Nature’s AM terms of use, but is not the Version of Record and does not reflect post-acceptance improvements, or any corrections. The Version of Record is available online at: https://doi.org/10.1038/s41567-025-02804-0.' identifier: http://rightsstatements.org/vocab/InC/1.0/ ## Other identifier(s) ## Data origin - data_origin_type: other ## Embargo start_date: 2025-03-20 end_date: 2025-09-20 ## Journal - title: Nature Physics issn: '17452481' volume: '21' issue: '4' start_page: 549 end_page: 555 ## Conference ## Related item ## Funding - identifier: DE-SC0018171 funder_name: DOE | SC | Basic Energy Sciences - identifier: DE-SC0019443 funder_name: DOE | SC | Basic Energy Sciences - identifier: AFOSR FA9550-21-1-0177 funder_name: United States Department of Defense | United States Air Force | AFMC | Air Force Office of Scientific Research - identifier: DGE-2140004 funder_name: NSF | Directorate for Education & Human Resources | Division of Graduate Education - identifier: 21H05233, 23H02052 funder_name: MEXT | Japan Society for the Promotion of Science - identifier: KAKENHI 21H05233, 23H02052 funder_name: MEXT | Japan Society for the Promotion of Science - identifier: Simons Investigator Grant No. 404513 funder_name: Simons Foundation ## Instrument ## Instrument operator ## Instrument managing organization ## Measurement method ## Specimen ## Chemical composition ## Structure for specimen ## Structural feature for specimen ## Specific property for specimen ## Process for specimen treatment ## Computational method ## Energy level/transition state ## Software ## Custom property ## Fileset - id: 5d4c33bd-b14e-4c37-b593-8a8c34c44f74 filename: 2025A01020G_AcceptedVersion_MDR.pdf content_type: application/pdf size: 4200811 md5: 2db0a7fc59c65727c900220bcc297f39 ## Thumbnail fileset_id: 5d4c33bd-b14e-4c37-b593-8a8c34c44f74 filename: 2025A01020G_AcceptedVersion_MDR.pdf