Engineering antiferromagnetic exchange coupling for single-pulse all-optical switching

Engineering antiferromagnetic exchange coupling for single-pulse all-optical switching | 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 Article Engineering antiferromagnetic exchange coupling for single-pulse all-optical switching Yongbing Xu, Guanqi Li, Jiajun Li, Zihai Li, Wei Xia, Junlin Wang, and 5 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-9202734/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted You are reading this latest preprint version Abstract Single-pulse all-optical switching (SP-AOS) offers an appealing route to ultrafast magnetic information writing, yet the magnetic parameter that fundamentally determines whether toggle switching occurs has remained unclear. Here we incorporate a Ru spacer into Co/Gd heterostructures to tune the interlayer exchange coupling strength J_(Gd-Co) through the combined contributions of direct Co–Gd coupling and oscillatory RKKY interactions. The SP-AOS switching signal shows an oscillation nature with the period of Ru thickness less than 1 nm in coincide with the RKKY-defined oscillatory coercive field and saturation magnetization. SP-AOS emerges above a critical antiferromagnetic (AFM) exchange coupling strength of J_(Gd-Co)≈0.69mJ/m2 and reaches 100% at J_(Gd-Co)≈1.14 mJ/m2, where the stronger AFM coupling also lowers the threshold fluence and broadens the operational energy window. Atomistic spin-dynamics simulations further show that the strong J_(Gd-Co) accelerates the demagnetization dynamics of both Co and Gd sublattices and promotes the formation of the transient ferromagnetic state to enable SP-AOS, whereas weak J_(Gd-Co) suppresses this transient state and forces the system into a slower, dissipative spin–orbit–driven pathway. These results demonstrate that the key determinant of SP-AOS is not merely associated with the demagnetization times of the two sublattices, but is directly linked to the strength of antiferromagnetic exchange coupling. This study establishes the antiferromagnetic exchange coupling strength as a practical and designable criterion for nanoscale materials engineering of ultrafast photomagnetic switching. Physical sciences/Physics/Condensed-matter physics/Spintronics Physical sciences/Materials science/Nanoscale materials/Magnetic properties and materials Physical sciences/Nanoscience and technology/Nanoscale materials/Magnetic properties and materials Full Text Additional Declarations There is NO Competing Interest. Supplementary Files Supportinginformation.docx Supporting information for: Engineering antiferromagnetic exchange coupling for single-pulse all-optical switching Cite Share Download PDF Status: Under Review 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-9202734","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":621149288,"identity":"2c648297-b217-40e5-b73a-bc2ea41b8734","order_by":0,"name":"Yongbing 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Here we incorporate a Ru spacer into Co/Gd heterostructures to tune the interlayer exchange coupling strength J_(Gd-Co) through the combined contributions of direct Co–Gd coupling and oscillatory RKKY interactions. The SP-AOS switching signal shows an oscillation nature with the period of Ru thickness less than 1 nm in coincide with the RKKY-defined oscillatory coercive field and saturation magnetization. SP-AOS emerges above a critical antiferromagnetic (AFM) exchange coupling strength of J_(Gd-Co)≈0.69mJ/m2 and reaches 100% at J_(Gd-Co)≈1.14 mJ/m2, where the stronger AFM coupling also lowers the threshold fluence and broadens the operational energy window. 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