Magnetic Signatures of a Putative Fractional Topological Insulator in Twisted MoTe2

Magnetic Signatures of a Putative Fractional Topological Insulator in Twisted MoTe2 | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Physical Sciences - Article Magnetic Signatures of a Putative Fractional Topological Insulator in Twisted MoTe2 Xiaoyang Zhu, Yiping Wang, Gillian Minarik, Weijie Li, Yves Kwan, and 13 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8701020/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract The interplay among electronic correlation, topology, and time-reversal-symmetry (TRS) often leads to exotic quantum states of matter. Primary examples include the recently realized fractional Chern insulators (FCIs) in twisted MoTe2 bilayers (tMoTe2) 1–4 and multilayer graphene aligned with hBN 5, where TRS is broken in partially filled flat moiré Chern bands. Among the FCIs in tMoTe2, the most robust is at a hole filling of v = -2/3 per moiré unit cell 1–4,6,7. Interestingly, transient optical sensing 8 and more recent transport measurements 9,10 revealed a correlated state at v = -4/3, twice the filling factor for the v = -2/3 FCI. Here, employing pump-probe circular dichroism (CD) measurements on tMoTe2 with twist angles θ = 3.9^o and 3.7^o, we find that the v = -4/3 state exhibits vanishing magnetization (m = 0) in finite windows of out-of-plane magnetic field |µ0H| ≤ ~2-4 mT, and a first order phase transition to ±m states at higher fields. This out-of-plane antiferromagnetic (AFM) like behavior is notably absent for all other correlated states and disappears for the v = -4/3 state at higher or lower twist angles of θ = 4.0^o and 3.3^o. The observed magnetic signature at v = -4/3 is consistent with a predicted fractional topological insulator (FTI) with TRS, consisting of two copies of -2/3 FCIs with opposite chiralities 11. We support these findings with calculations in the interacting continuum model of tMoTe2. Our work presents a candidate for fractional topological insulators with TRS 12–14. Physical sciences/Physics/Condensed-matter physics/Topological matter/Topological insulators Physical sciences/Materials science/Condensed-matter physics/Topological matter/Topological insulators Full Text Additional Declarations There is NO Competing Interest. Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-8701020","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Physical Sciences - Article","associatedPublications":[],"authors":[{"id":580643528,"identity":"1473a3f3-ee05-420d-bfaa-0c07d10dfffd","order_by":0,"name":"Xiaoyang 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Primary examples include the recently realized fractional Chern insulators (FCIs) in twisted MoTe2 bilayers (tMoTe2) 1–4 and multilayer graphene aligned with hBN 5, where TRS is broken in partially filled flat moiré Chern bands. Among the FCIs in tMoTe2, the most robust is at a hole filling of v = -2/3 per moiré unit cell 1–4,6,7. Interestingly, transient optical sensing 8 and more recent transport measurements 9,10 revealed a correlated state at v = -4/3, twice the filling factor for the v = -2/3 FCI. Here, employing pump-probe circular dichroism (CD) measurements on tMoTe2 with twist angles θ = 3.9^o and 3.7^o, we find that the v = -4/3 state exhibits vanishing magnetization (m = 0) in finite windows of out-of-plane magnetic field |µ0H| ≤ ~2-4 mT, and a first order phase transition to ±m states at higher fields. This out-of-plane antiferromagnetic (AFM) like behavior is notably absent for all other correlated states and disappears for the v = -4/3 state at higher or lower twist angles of θ = 4.0^o and 3.3^o. The observed magnetic signature at v = -4/3 is consistent with a predicted fractional topological insulator (FTI) with TRS, consisting of two copies of -2/3 FCIs with opposite chiralities 11. We support these findings with calculations in the interacting continuum model of tMoTe2. Our work presents a candidate for fractional topological insulators with TRS 12–14.","manuscriptTitle":"Magnetic Signatures of a Putative Fractional Topological Insulator in Twisted MoTe2","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-01-28 04:03:39","doi":"10.21203/rs.3.rs-8701020/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"397189ad-e36d-4063-91ed-00cfe40b581a","owner":[],"postedDate":"January 28th, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[{"id":61769352,"name":"Physical sciences/Physics/Condensed-matter physics/Topological matter/Topological insulators"},{"id":61769353,"name":"Physical sciences/Materials science/Condensed-matter physics/Topological matter/Topological insulators"}],"tags":[],"updatedAt":"2026-03-02T08:15:26+00:00","versionOfRecord":[],"versionCreatedAt":"2026-01-28 04:03:39","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-8701020","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8701020","identity":"rs-8701020","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}