Robust field-free superconducting diode effect in FeTe0.55Se0.45

Robust field-free superconducting diode effect in FeTe0.55Se0.45 | 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 Robust field-free superconducting diode effect in FeTe 0.55 Se 0.45 Peng Dong, Jinghui Wang, Yanjiang Wang, Jianjun Xiao, Xiang Zhou, and 7 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8787923/v1 This work is licensed under a CC BY 4.0 License Status: Under Revision Version 1 posted 10 You are reading this latest preprint version Abstract The superconducting diode effect (SDE), a nonreciprocal phenomenon where the critical supercurrent differs with the direction of current flow, is a promising foundation for superconducting logic and memory. Realizing its full potential requires a diode that operates without an applied magnetic field, demanding the breaking of both time reversal and inversion symmetries within the super-conductors. Zero-field SDE is often observed in heterostructures, while rare in single materials. Here, we report the observation of a robust, field-free SDE in thin flake FeTe 0.55 Se 0.45. A definitive signature of the effect is the emergence of a pronounced second harmonic response near the superconducting transition under zero applied field, with an amplitude comparable to the standard first harmonic signal. The SDE persists at zero field, and maintains its polarization robustly under both high positive and negative magnetic field—an even symmetry with respect to the magnetic field, a key distinction from mechanisms based on finite-momentum pairing or magnetochiral anisotropy. We systematically exclude alternative origins from device geometry, thermal gradient, chiral domains or extrinsic magnetic order. Instead, our analysis indicates that local strain/polarization-induced symmetry breaking is a primary factor in generating and enhancing the effect. These results establish FeTe 0.55 Se 0.45 as a compelling, structurally simple material platform for intrinsic field-free superconducting diodes. Physical sciences/Materials science Physical sciences/Physics field free superconducting diode effect (SDE) symmetry breaking local strain/polarization Full Text Additional Declarations No competing interests reported. Supplementary Files FTSSDESI.pdf Cite Share Download PDF Status: Under Revision Version 1 posted Editorial decision: Revision requested 29 Apr, 2026 Reviews received at journal 23 Apr, 2026 Reviews received at journal 06 Apr, 2026 Reviewers agreed at journal 09 Mar, 2026 Reviewers agreed at journal 01 Mar, 2026 Reviewers agreed at journal 23 Feb, 2026 Reviewers invited by journal 11 Feb, 2026 Editor assigned by journal 11 Feb, 2026 Submission checks completed at journal 09 Feb, 2026 First submitted to journal 04 Feb, 2026 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-8787923","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":590062140,"identity":"6bd396d3-ab4a-45fa-96bb-50c326546337","order_by":0,"name":"Peng Dong","email":"","orcid":"","institution":"ShanghaiTech University","correspondingAuthor":false,"prefix":"","firstName":"Peng","middleName":"","lastName":"Dong","suffix":""},{"id":590062141,"identity":"240e83e9-bc69-4cc2-ac1a-48510395c431","order_by":1,"name":"Jinghui Wang","email":"","orcid":"","institution":"ShanghaiTech University","correspondingAuthor":false,"prefix":"","firstName":"Jinghui","middleName":"","lastName":"Wang","suffix":""},{"id":590062142,"identity":"769d10c9-061d-435b-8a26-96f81a184503","order_by":2,"name":"Yanjiang Wang","email":"","orcid":"","institution":"ShanghaiTech University","correspondingAuthor":false,"prefix":"","firstName":"Yanjiang","middleName":"","lastName":"Wang","suffix":""},{"id":590062143,"identity":"606997be-be8b-41d3-a601-92cc3059e6a3","order_by":3,"name":"Jianjun Xiao","email":"","orcid":"","institution":"ShanghaiTech University","correspondingAuthor":false,"prefix":"","firstName":"Jianjun","middleName":"","lastName":"Xiao","suffix":""},{"id":590062144,"identity":"a6e0d7da-2e82-41c1-902c-8de4b2205e69","order_by":4,"name":"Xiang Zhou","email":"","orcid":"","institution":"ShanghaiTech University","correspondingAuthor":false,"prefix":"","firstName":"Xiang","middleName":"","lastName":"Zhou","suffix":""},{"id":590062145,"identity":"d16d5181-1ad9-47ae-b13f-106bf92bc6dc","order_by":5,"name":"Hui Xing","email":"","orcid":"","institution":"Shanghai Jiao Tong University","correspondingAuthor":false,"prefix":"","firstName":"Hui","middleName":"","lastName":"Xing","suffix":""},{"id":590062146,"identity":"746d663b-de34-4b3a-bacc-3742e0089381","order_by":6,"name":"Kenji Watanabe","email":"","orcid":"","institution":"National Institute for Materials Science","correspondingAuthor":false,"prefix":"","firstName":"Kenji","middleName":"","lastName":"Watanabe","suffix":""},{"id":590062147,"identity":"8d2c0992-6996-4b33-a3fa-7bae6b5ad81f","order_by":7,"name":"Takashi Taniguchi","email":"","orcid":"","institution":"National Institute for Materials Science","correspondingAuthor":false,"prefix":"","firstName":"Takashi","middleName":"","lastName":"Taniguchi","suffix":""},{"id":590062148,"identity":"9bbb2032-a101-43a7-a190-dc988bcecb26","order_by":8,"name":"Yueshen Wu","email":"","orcid":"","institution":"ShanghaiTech University","correspondingAuthor":false,"prefix":"","firstName":"Yueshen","middleName":"","lastName":"Wu","suffix":""},{"id":590062150,"identity":"9a06ac55-a7f4-4450-9cab-06fd794ab4ba","order_by":9,"name":"Yulin Chen","email":"","orcid":"","institution":"University of Oxford","correspondingAuthor":false,"prefix":"","firstName":"Yulin","middleName":"","lastName":"Chen","suffix":""},{"id":590062151,"identity":"5f73a7b7-9329-4663-b84f-fcba03f9bb96","order_by":10,"name":"Jinshen Wen","email":"","orcid":"","institution":"Nanjing University","correspondingAuthor":false,"prefix":"","firstName":"Jinshen","middleName":"","lastName":"Wen","suffix":""},{"id":590062153,"identity":"d59e849e-c73c-40e4-9949-43af77fed04b","order_by":11,"name":"Jun Li","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAABFElEQVRIiWNgGAWjYBACPmaGBAaGHzYMBkAOMwODBJDiAWI23FrYQFoYe9LgWiQIa4GQh2FaGIjQws7wTLqA57y9OfvZw68Laizq+NnPHmD4UHaYgX92Ay6HpUnPsLiduLMnL816xjEJCcmevATGGecOM0jcOYBbCw/P7QSDAzlmxjxsEhIGN3gMmHnbgE6VSMCjhe2cvcH5N0At/yQk7EFa/hLWcoBxw40c48e8bUBbJIBaGPFrSbbm7UlO3HDjjRkzb5+E5IwzOQYHe86l80jcwK6Fn/9M4m2eH3ZAh+UYf+b5VsfP337G8MGPMms5/hnYtQBjAS7BJgFjHWCAxA4OwH4AxmL+gFvVKBgFo2AUjGQAADr2UGxUaXaQAAAAAElFTkSuQmCC","orcid":"","institution":"ShanghaiTech University","correspondingAuthor":true,"prefix":"","firstName":"Jun","middleName":"","lastName":"Li","suffix":""}],"badges":[],"createdAt":"2026-02-04 14:53:54","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-8787923/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-8787923/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":102962761,"identity":"c5564b39-637a-4002-9e20-d4fe8a82074d","added_by":"auto","created_at":"2026-02-19 04:11:00","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1379103,"visible":true,"origin":"","legend":"","description":"","filename":"snarticle.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8787923/v1_covered_3d47f9dd-723f-4177-b7cc-9ea62120fe43.pdf"},{"id":102735479,"identity":"8036598c-92f1-42ee-9579-5af0477fa8ab","added_by":"auto","created_at":"2026-02-16 06:15:50","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"supplement","size":1119980,"visible":true,"origin":"","legend":"","description":"","filename":"FTSSDESI.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8787923/v1/8f6b6303be07372506b0551f.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"\u003cp\u003eRobust field-free superconducting diode effect in FeTe\u003csub\u003e0.55\u003c/sub\u003eSe\u003csub\u003e0.45\u003c/sub\u003e\u003c/p\u003e","fulltext":[],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":true,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":true,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"npj-quantum-materials","isNatureJournal":false,"hasQc":false,"allowDirectSubmit":false,"externalIdentity":"npjquantmats","sideBox":"Learn more about [npj Quantum Materials](http://www.nature.com/npjquantmats/)","snPcode":"41535","submissionUrl":"https://mts-npjquantmats.nature.com/cgi-bin/main.plex","title":"npj Quantum Materials","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"ejp","reportingPortfolio":"NPJ","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"field free superconducting diode effect (SDE), symmetry breaking, local strain/polarization","lastPublishedDoi":"10.21203/rs.3.rs-8787923/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8787923/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"The superconducting diode effect (SDE), a nonreciprocal phenomenon where the critical supercurrent differs with the direction of current flow, is a promising foundation for superconducting logic and memory. Realizing its full potential requires a diode that operates without an applied magnetic field, demanding the breaking of both time reversal and inversion symmetries within the super-conductors. Zero-field SDE is often observed in heterostructures, while rare in single materials. Here, we report the observation of a robust, field-free SDE in thin flake FeTe 0.55 Se 0.45. A definitive signature of the effect is the emergence of a pronounced second harmonic response near the superconducting transition under zero applied field, with an amplitude comparable to the standard first harmonic signal. The SDE persists at zero field, and maintains its polarization robustly under both high positive and negative magnetic field—an even symmetry with respect to the magnetic field, a key distinction from mechanisms based on finite-momentum pairing or magnetochiral anisotropy. We systematically exclude alternative origins from device geometry, thermal gradient, chiral domains or extrinsic magnetic order. Instead, our analysis indicates that local strain/polarization-induced symmetry breaking is a primary factor in generating and enhancing the effect. These results establish FeTe 0.55 Se 0.45 as a compelling, structurally simple material platform for intrinsic field-free superconducting diodes.","manuscriptTitle":"Robust field-free superconducting diode effect in FeTe0.55Se0.45","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-02-16 06:15:45","doi":"10.21203/rs.3.rs-8787923/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2026-04-29T09:46:27+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-04-24T03:33:56+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-04-06T18:25:46+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"136884543148388094511356802245837522921","date":"2026-03-09T12:40:17+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"136180968883925189048649069440577468157","date":"2026-03-01T06:57:34+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"303876834479644788340296211290806482797","date":"2026-02-23T14:28:48+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2026-02-11T11:13:24+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2026-02-11T10:32:01+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2026-02-09T15:18:47+00:00","index":"","fulltext":""},{"type":"submitted","content":"npj Quantum Materials","date":"2026-02-04T14:38:58+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"npj-quantum-materials","isNatureJournal":false,"hasQc":false,"allowDirectSubmit":false,"externalIdentity":"npjquantmats","sideBox":"Learn more about [npj Quantum Materials](http://www.nature.com/npjquantmats/)","snPcode":"41535","submissionUrl":"https://mts-npjquantmats.nature.com/cgi-bin/main.plex","title":"npj Quantum Materials","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"ejp","reportingPortfolio":"NPJ","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"7478d5e9-4c12-4bae-9232-f3431ffd070c","owner":[],"postedDate":"February 16th, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"in-revision","subjectAreas":[{"id":62979457,"name":"Physical sciences/Materials science"},{"id":62979458,"name":"Physical sciences/Physics"}],"tags":[],"updatedAt":"2026-04-29T09:54:16+00:00","versionOfRecord":[],"versionCreatedAt":"2026-02-16 06:15:45","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-8787923","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8787923","identity":"rs-8787923","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}