Tracking the Catastrophic Collapse of Hybrid Exciton-Phonon Order in a Quantum Material

Tracking the Catastrophic Collapse of Hybrid Exciton-Phonon Order in a Quantum Material | 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 Physical Sciences - Article Tracking the Catastrophic Collapse of Hybrid Exciton-Phonon Order in a Quantum Material Hamoon Hedayat, Omar Abdul-Aziz, Danilo Comini, Johannes Lang, and 7 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8344272/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 Revealing the hidden interactions that bind the electronic and lattice components of a cooperative quantum order is central to sculpting new states of matter. This challenge is epitomized by the charge density wave material 1T-TiSe 2 , where photoexcitation disrupts its presumed hybrid exciton-phonon order, exposing a striking paradox: the electronic component collapses within femtoseconds, while the periodic lattice distortion persists, challenging the very definition of a hybrid order: if the lattice distortion outlives the excitonic condensate, were they ever truly intertwined? Here we resolve this paradox by uncovering a low-frequency mode (0.13 THz) that emerges only in the ordered state and signals the presence of exciton-phonon coupling. This mode is consistent with a locked phason, a collective excitation that would arise if the coupling between the excitonic condensate and the lattice reduced its continuous phase symmetry to a discrete one, thereby giving the excitonic Goldstone mode a finite mass. Such a scenario is captured by an effective theory, which describes a shared potential landscape linking the excitonic and lattice degrees of freedom. At a critical photoexcitation threshold, the collapse of the excitonic order flattens the potential, triggering an exciton-phonon catastrophe characterized by selective overheating of the charge density wave phonon, the disappearance of the locked phason, and a sudden loss of electronic coherence. Remarkably, the lattice distortion survives this event as a dynamically trapped and non-thermal remnant, whose non-equilibrium character is confirmed by the anomalous temperature dependence of the phononic response. These findings demonstrate that the coupled potential energy landscape of cooperative orders can be manipulated to selectively dismantle complex quantum orders, advancing a new paradigm for material control through dynamical design. Physical sciences/Materials science/Condensed-matter physics/Phase transitions and critical phenomena Physical sciences/Physics/Condensed-matter physics/Electronic properties and materials Full Text Additional Declarations There is NO Competing Interest. Supplementary Files SupplementaryInformationTracking.pdf Supplementary Information for Tracking the Catastrophic Collapse of Hybrid Exciton-Phonon Order in a Quantum Material 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-8344272","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Physical Sciences - Article","associatedPublications":[],"authors":[{"id":562382239,"identity":"701c69a4-5867-413e-9304-c662dd197db4","order_by":0,"name":"Hamoon 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