De Novo Design of a Non-Cryogenic Quantum Interface: Tuning Erbium Emission to the Telecom C-Band within a Synthetic Protein Scaffold

De Novo Design of a Non-Cryogenic Quantum Interface: Tuning Erbium Emission to the Telecom C-Band within a Synthetic Protein Scaffold | 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 De Novo Design of a Non-Cryogenic Quantum Interface: Tuning Erbium Emission to the Telecom C-Band within a Synthetic Protein Scaffold Alberto Renee Mora Peña This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8689370/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 development of scalable quantum networks is fundamentally limited by the cryogenic infrastructure required by current solid-state quantum emitters, restricting deployment beyond laboratory settings. Here, we present a computational demonstration of non-cryogenic (277 K) quantum-compatible emission at telecommunication wavelengths from erbium(III) ions embedded in a de novo designed protein scaffold. Building upon our previously proposed "Biological Anchor" architecture for hybrid bio-quantum communication systems 3 ¹, we designed and computationally characterized a chimeric protein, which we term Teledrybin, featuring a modified EF-hand motif optimized for asymmetric 9-coordinate Er³⁺ binding. Using complete active space self-consistent field (CASSCF) calculations with N-electron valence state perturbation theory (NEVPT2) and spin-orbit coupling (SOC), we predict optical transitions at 1554 nm, precisely within the telecommunications C-band (1530–1565 nm). Molecular dynamics simulations at 277 K in H₂O (to be replaced by D₂O on field) demonstrate structural stability over 140 ns, with the Er³⁺ coordination geometry converging to average Er–O distances of 2.34–2.36 Å and angular deviations below 2° across independent AlphaFold3 models. The low-symmetry (C₁) coordination environment enables the otherwise Laporte-forbidden 4f-4f transitions, while the engineered hydrophobic barrier suppresses vibrational quenching by excluding bulk solvent from the binding site—only a single structural D₂O molecule remains coordinated. These results validate the feasibility of protein-based quantum emitters operating under non-cryogenic conditions in the telecom band, offering a biologically-producible, scalable alternative to solid-state quantum light sources for edge-node applications in quantum networks. Biotechnology and Bioengineering Quantum emitter Erbium Telecom C-band 1550nm protein design De novo protein CASSCF NEVPT2 SOC ORCA Molecular dynamics Full Text Additional Declarations The authors declare no competing interests. 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-8689370","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":579925143,"identity":"3a64ec49-8f14-4dc5-862f-845f7cd7d4fd","order_by":0,"name":"Alberto Renee Mora Peña","email":"data:image/png;base64,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","orcid":"","institution":"Universidad del Zulia","correspondingAuthor":true,"prefix":"","firstName":"Alberto","middleName":"Renee Mora","lastName":"Peña","suffix":""}],"badges":[],"createdAt":"2026-01-24 23:08:53","currentVersionCode":1,"declarations":{"humanSubjects":false,"vertebrateSubjects":false,"conflictsOfInterestStatement":false,"humanSubjectEthicalGuidelines":false,"humanSubjectConsent":false,"humanSubjectClinicalTrial":false,"humanSubjectCaseReport":false,"vertebrateSubjectEthicalGuidelines":false},"doi":"10.21203/rs.3.rs-8689370/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-8689370/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":101296836,"identity":"d7e95ccd-d99e-4d48-8451-0f5e3a0bb8fe","added_by":"auto","created_at":"2026-01-28 09:21:25","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1930460,"visible":true,"origin":"","legend":"","description":"","filename":"AlbertomoraTeledry3.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8689370/v1_covered_f5186af8-19c8-4262-8238-f058cec52582.pdf"}],"financialInterests":"The authors declare no competing interests.","formattedTitle":"\u003cp\u003eDe Novo Design of a Non-Cryogenic Quantum Interface: Tuning Erbium Emission to the Telecom C-Band within a Synthetic Protein Scaffold\u003c/p\u003e","fulltext":[],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":true,"hideJournal":true,"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":"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},"keywords":"Quantum emitter, Erbium,Telecom C-band 1550nm, protein design, De novo protein, CASSCF, NEVPT2, SOC, ORCA, Molecular dynamics","lastPublishedDoi":"10.21203/rs.3.rs-8689370/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8689370/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eThe development of scalable quantum networks is fundamentally limited by the cryogenic infrastructure required by current solid-state quantum emitters, restricting deployment beyond laboratory settings. Here, we present a computational demonstration of non-cryogenic (277 K) quantum-compatible emission at telecommunication wavelengths from erbium(III) ions embedded in a de novo designed protein scaffold. Building upon our previously proposed \"Biological Anchor\" architecture for hybrid bio-quantum communication systems\u003csup\u003e3\u003c/sup\u003e¹, we designed and computationally characterized a chimeric protein, which we term Teledrybin, featuring a modified EF-hand motif optimized for asymmetric 9-coordinate Er³⁺ binding. Using complete active space self-consistent field (CASSCF) calculations with N-electron valence state perturbation theory (NEVPT2) and spin-orbit coupling (SOC), we predict optical transitions at 1554 nm, precisely within the telecommunications C-band (1530–1565 nm). Molecular dynamics simulations at 277 K in H₂O (to be replaced by D₂O on field) demonstrate structural stability over 140 ns, with the Er³⁺ coordination geometry converging to average Er–O distances of 2.34–2.36 Å and angular deviations below 2° across independent AlphaFold3 models. The low-symmetry (C₁) coordination environment enables the otherwise Laporte-forbidden 4f-4f transitions, while the engineered hydrophobic barrier suppresses vibrational quenching by excluding bulk solvent from the binding site—only a single structural D₂O molecule remains coordinated. 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