Observation of a spin chirality driven topological transition in a van der Waals magnet

Observation of a spin chirality driven topological transition in a van der Waals magnet | 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 Observation of a spin chirality driven topological transition in a van der Waals magnet Yusuke Nambu, Kazushi Aoyama, Hikaru Kawamura, Thomas Gentile, and 4 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-1535863/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 Low-dimensional magnetism has long been the central issue in condensed matter physics, and van der Waals materials provide an ideal platform for exploring magnetism at the two-dimensional limit. The magnetic order in two-dimensional model materials is suppressed, and arguments based upon topology are useful for describing phases of matter. An example is the Berezinskii-Kosterlitz-Thouless transition where spin correlations over long distances eventually give rise to magnetic order; thus has never been realised experimentally in magnetic materials. A similar topological transition with vortices by chirality, handedness of the electronic spin arrangements, is possible without inducing any order; however, evidence for this higher-order vortex dissociation transition remains elusive. Here, we combine polarised neutron scattering and theoretical simulations to show that the transition occurs in a van der Waals magnet. We experimentally observe in-plane and out-of-plane spin moments, and their ratio, the spin-state anisotropy, shows a tendency for reversal across an anomalous temperature. Our simulations confirm the experimental findings; the tendency cannot be reproduced when removing the chiral vortices. The chirality-driven topological transition is general but has been challenging to be detected. Our results set a new paradigm for revealing topological characteristics with a higher-order degree of freedom. Full Text Additional Declarations There is NO Competing Interest. Supplementary Files supplementary.pdf Supplementary Information 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. 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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-1535863","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Physical Sciences - Article","associatedPublications":[],"authors":[{"id":97118275,"identity":"164db7a4-2698-4d3c-a442-70852c9b96b9","order_by":0,"name":"Yusuke 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The magnetic order in two-dimensional model materials is suppressed, and arguments based upon topology are useful for describing phases of matter. An example is the Berezinskii-Kosterlitz-Thouless transition where spin correlations over long distances eventually give rise to magnetic order; thus has never been realised experimentally in magnetic materials. A similar topological transition with vortices by chirality, handedness of the electronic spin arrangements, is possible without inducing any order; however, evidence for this higher-order vortex dissociation transition remains elusive. Here, we combine polarised neutron scattering and theoretical simulations to show that the transition occurs in a van der Waals magnet. We experimentally observe in-plane and out-of-plane spin moments, and their ratio, the spin-state anisotropy, shows a tendency for reversal across an anomalous temperature. Our simulations confirm the experimental findings; the tendency cannot be reproduced when removing the chiral vortices. The chirality-driven topological transition is general but has been challenging to be detected. Our results set a new paradigm for revealing topological characteristics with a higher-order degree of freedom.","manuscriptTitle":"Observation of a spin chirality driven topological transition in a van der Waals magnet","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2022-04-11 13:41:13","doi":"10.21203/rs.3.rs-1535863/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":"627798ef-30fb-4f4a-ba1a-751431656ea7","owner":[],"postedDate":"April 11th, 2022","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2022-05-09T14:51:32+00:00","versionOfRecord":[],"versionCreatedAt":"2022-04-11 13:41:13","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-1535863","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-1535863","identity":"rs-1535863","version":["v1"]},"buildId":"rHA-KDH7Qsr4HCuvH75dn","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}