Robustness of Continuous Variable Quantum Key Distribution Under Strong Polarization Drift

Robustness of Continuous Variable Quantum Key Distribution Under Strong Polarization Drift | 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 Research Article Robustness of Continuous Variable Quantum Key Distribution Under Strong Polarization Drift Margarida Almeida, Armando N. Pinto, Nuno A. Silva This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6829487/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 15 Oct, 2025 Read the published version in EPJ Quantum Technology → Version 1 posted 10 You are reading this latest preprint version Abstract The practical deployment of Continuous Variables Quantum Key Distribution (CV-QKD) systems benefits from existing optical fiber telecommunication infrastructures. However, optical fibers introduce random variations in the state of polarization, which degrades the system's performance.We consider a CV-QKD system featuring a polarization diversity heterodyne receiver and the constant modulus algorithm (CMA) to compensate for the polarization drifts in the quantum channel. Our setup can effectively realign Alice's quantum signal with Bob's local oscillator for polarization drift variances below \(10^{-10}\) .This value is compatible with most experimental implementations, allowing for accurate estimation of the channel transmission and excess noise parameters. This validates the approximation of real-world implementations under polarization drift to an ideal scenario without polarization drift, ensuring that the security proof remains applicable for polarization drift variances below $ 10^{-10} $ .Our results establish operational limits for passive polarization drift compensation using a polarization diversity receiver combined with digital CMA.This enables long-term stability in \linebreak CV-QKD systems, eliminating the need for active polarization controllers and manual adjustments. Quantum Key Distribution Quantum Continuous Variables Polarization Drift Polarization Diversity Constant Modulus Algorithm Full Text Additional Declarations No competing interests reported. Cite Share Download PDF Status: Published Journal Publication published 15 Oct, 2025 Read the published version in EPJ Quantum Technology → Version 1 posted Editorial decision: Revision requested 07 Jul, 2025 Reviews received at journal 24 Jun, 2025 Reviews received at journal 22 Jun, 2025 Reviewers agreed at journal 17 Jun, 2025 Reviewers agreed at journal 14 Jun, 2025 Reviewers agreed at journal 12 Jun, 2025 Reviewers invited by journal 11 Jun, 2025 Editor assigned by journal 10 Jun, 2025 Submission checks completed at journal 10 Jun, 2025 First submitted to journal 05 Jun, 2025 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-6829487","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":470608592,"identity":"8f0a82a0-2833-4a91-9374-13dd4805e3cf","order_by":0,"name":"Margarida Almeida","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAuUlEQVRIiWNgGAWjYHACxgMMDBKMDewNJOiBaOE5AGIbEK2FgbFBIoFILbqzDz84dKPCQrZ/5hvDD4w7/hDWYnYuzeBwzhkJ4xm3c4wlGM8QYYvZGQaDw7ltEokNt3MMJBjbiNLC/uFw7j+JxPk3zxj/IFILD9CWBonEDTd4zIi1hafgcM4xCeONZ9LKLBLPGBPlsI2Pc2rqZOcdP7z5xscdcoS1oILEBlJ1ACOUZC2jYBSMglEwAgAAQuM+e8AFd50AAAAASUVORK5CYII=","orcid":"","institution":"Instituto de Telecomunicações","correspondingAuthor":true,"prefix":"","firstName":"Margarida","middleName":"","lastName":"Almeida","suffix":""},{"id":470608593,"identity":"62fcb8fb-ce57-47bc-b607-d6adf339087c","order_by":1,"name":"Armando N. Pinto","email":"","orcid":"","institution":"Instituto de Telecomunicações","correspondingAuthor":false,"prefix":"","firstName":"Armando","middleName":"N.","lastName":"Pinto","suffix":""},{"id":470608594,"identity":"84846bfd-5361-4139-ab75-5a13180c5e72","order_by":2,"name":"Nuno A. Silva","email":"","orcid":"","institution":"Instituto de Telecomunicações","correspondingAuthor":false,"prefix":"","firstName":"Nuno","middleName":"A.","lastName":"Silva","suffix":""}],"badges":[],"createdAt":"2025-06-05 13:08:32","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-6829487/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-6829487/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1140/epjqt/s40507-025-00417-3","type":"published","date":"2025-10-15T15:57:00+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":93955964,"identity":"9f26df76-0d26-40d1-a24c-44b52e6ce28b","added_by":"auto","created_at":"2025-10-20 16:08:21","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":2393434,"visible":true,"origin":"","legend":"","description":"","filename":"2025MAlmeidaRobustnessManuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-6829487/v1_covered_73265c48-8227-4f87-b546-95f558569d1d.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Robustness of Continuous Variable Quantum Key Distribution Under Strong Polarization Drift","fulltext":[],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":true,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":true,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"epj-quantum-technology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"epjq","sideBox":"Learn more about [EPJ Quantum Technology](http://epjquantumtechnology.springeropen.com)","snPcode":"40507","submissionUrl":"https://submission.nature.com/new-submission/40507/3","title":"EPJ Quantum Technology","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Quantum Key Distribution, Quantum Continuous Variables, Polarization Drift, Polarization Diversity, Constant Modulus Algorithm","lastPublishedDoi":"10.21203/rs.3.rs-6829487/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-6829487/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eThe practical deployment of Continuous Variables Quantum Key Distribution (CV-QKD) systems benefits from existing optical fiber telecommunication infrastructures. However, optical fibers introduce random variations in the state of polarization, which degrades the system's performance.We consider a CV-QKD system featuring a polarization diversity heterodyne receiver and the constant modulus algorithm (CMA) to compensate for the polarization drifts in the quantum channel. Our setup can effectively realign Alice's quantum signal with Bob's local oscillator for polarization drift variances below \u003cspan class=\"InlineEquation\"\u003e \u003cspan class=\"mathinline\"\u003e \\(10^{-10}\\) \u003c/span\u003e \u003c/span\u003e.This value is compatible with most experimental implementations, allowing for accurate estimation of the channel transmission and excess noise parameters. This validates the approximation of real-world implementations under polarization drift to an ideal scenario without polarization drift, ensuring that the security proof remains applicable for polarization drift variances below \u003cspan\u003e$\u003c/span\u003e 10^{-10} \u003cspan\u003e$\u003c/span\u003e.Our results establish operational limits for passive polarization drift compensation using a polarization diversity receiver combined with digital CMA.This enables long-term stability in \\linebreak CV-QKD systems, eliminating the need for active polarization controllers and manual adjustments.\u003c/p\u003e","manuscriptTitle":"Robustness of Continuous Variable Quantum Key Distribution Under Strong Polarization Drift","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-06-13 05:31:43","doi":"10.21203/rs.3.rs-6829487/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2025-07-07T07:57:36+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-06-24T17:36:57+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-06-22T13:09:57+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"151793351786386240936343708059098768177","date":"2025-06-17T13:46:26+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"236847664228127017582734000497861195505","date":"2025-06-14T21:16:08+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"199641946134600707634182842167661836793","date":"2025-06-12T10:01:06+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-06-11T04:36:42+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-06-10T11:45:20+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-06-10T11:43:16+00:00","index":"","fulltext":""},{"type":"submitted","content":"EPJ Quantum Technology","date":"2025-06-05T13:05:56+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"epj-quantum-technology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"epjq","sideBox":"Learn more about [EPJ Quantum Technology](http://epjquantumtechnology.springeropen.com)","snPcode":"40507","submissionUrl":"https://submission.nature.com/new-submission/40507/3","title":"EPJ Quantum Technology","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"19616beb-0605-4e25-9a78-b2d744b85ee9","owner":[],"postedDate":"June 13th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2025-10-20T16:00:37+00:00","versionOfRecord":{"articleIdentity":"rs-6829487","link":"https://doi.org/10.1140/epjqt/s40507-025-00417-3","journal":{"identity":"epj-quantum-technology","isVorOnly":false,"title":"EPJ Quantum Technology"},"publishedOn":"2025-10-15 15:57:00","publishedOnDateReadable":"October 15th, 2025"},"versionCreatedAt":"2025-06-13 05:31:43","video":"","vorDoi":"10.1140/epjqt/s40507-025-00417-3","vorDoiUrl":"https://doi.org/10.1140/epjqt/s40507-025-00417-3","workflowStages":[]},"version":"v1","identity":"rs-6829487","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-6829487","identity":"rs-6829487","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}