Exceptional Bound States in the Continuum in a Passive Terahertz Metasurface

Exceptional Bound States in the Continuum in a Passive Terahertz Metasurface | 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 Exceptional Bound States in the Continuum in a Passive Terahertz Metasurface Chen Chen, Liu Ziyi, Jianfei Li, Zhou Junhan, Jiang Yuanhang, and 6 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-9232537/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 Exceptional bound states in the continuum (EP-BICs) are hybrid singularities in non-Hermitian systems that uniquely combine the non-radiating characteristic of bound states in the continuum (BICs) with the enhanced sensitivity of exceptional points (EPs). However, their experimental realization remains challenging because existing proposals typically require precise external excitation to control the loss and coupling strength. Here, we experimentally demonstrate an EP-BIC in a fully passive terahertz metasurface. Through simple geometric rotation, we modulate the internal coupling of two resonator modes to drive an isolated EP to coalesce with a line of BICs and finally form an EP-BIC, as clearly traced by transmission spectra measurements. Near-field terahertz scanning further observes the uniform phase distribution of EP-BIC, confirming its decoupling from incident light. Finally, the sensor performance of EP-BIC is demonstrated in water mist detection and exhibits a distinct dip response that enables unambiguous signal identification, in contrast to the weak and spectrally crowded peak of conventional EP. Our work establishes a practical and robust platform for EP-BICs, opening avenues for ultra-sensitive photonic sensing. Physical sciences/Optics and photonics/Optical physics/Terahertz optics Physical sciences/Optics and photonics/Optical physics/Nanophotonics and plasmonics Full Text Additional Declarations There is NO Competing Interest. Supplementary Files veido.mp4 The Sensing Sensitivity Advantage of EP-BIC for Water Mist SupplementalMaterialofExceptionalBoundStatesinthecontinuuminapassiveterahertzmetasurface.pdf Theoretical Derivation and Experimental Demonstration of EP‑BIC 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-9232537","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":619073148,"identity":"ee355b0f-e4aa-4631-80dc-0692b58dae30","order_by":0,"name":"Chen 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