Reducing TLS loss in tantalum CPW resonators using titanium sacrificial layers
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Quantum Physics arXiv:2601.16369 (quant-ph) [Submitted on 22 Jan 2026] Title:Reducing TLS loss in tantalum CPW resonators using titanium sacrificial layers Authors:Zachary Degnan, Chun-Ching Chiu, Yi-Hsun Chen, David Sommers, Leonid Abdurakhimov, Lihuang Zhu, Arkady Fedorov, Peter Jacobson View a PDF of the paper titled Reducing TLS loss in tantalum CPW resonators using titanium sacrificial layers, by Zachary Degnan and 7 other authors View PDF Abstract:We demonstrate a substantial reduction in two-level system loss in tantalum coplanar waveguide resonators fabricated on high-resistivity silicon substrates through the use of an ultrathin titanium sacrificial layer. A 0.2nm titanium film, deposited atop pre-sputtered {\alpha}-tantalum, acts as a solid-state oxygen getter that chemically modifies the native Ta oxide at the metal-air interface. After device fabrication, the titanium layer is removed using buffered oxide etchant, leaving behind a chemically reduced Ta oxide surface. Subsequent high-vacuum annealing further suppresses two-level system loss. Resonators treated with this process exhibit internal quality factors Qi exceeding an average of 1.5 million in the single-photon regime across ten devices, over three times higher than otherwise identical devices lacking the titanium layer. These results highlight the critical role of interfacial oxide chemistry in superconducting loss and reinforce atomic-scale surface engineering as an effective approach to improving coherence in tantalum-based quantum circuits. The method is compatible with existing fabrication workflows applicable to tantalum films, offering a practical route to further extending T1 lifetimes in superconducting qubits. Comments: Subjects: Quantum Physics (quant-ph); Materials Science (cond-mat.mtrl-sci); Superconductivity (cond-mat.supr-con) Cite as: arXiv:2601.16369 [quant-ph] (or arXiv:2601.16369v1 [quant-ph] for this version) https://doi.org/10.48550/arXiv.2601.16369 Focus to learn more arXiv-issued DOI via DataCite (pending registration) Submission history From: Zachary Degnan Mr. [view email] [v1] Thu, 22 Jan 2026 23:45:36 UTC (3,367 KB) Full-text links: Access Paper: View a PDF of the paper titled Reducing TLS loss in tantalum CPW resonators using titanium sacrificial layers, by Zachary Degnan and 7 other authorsView PDFTeX Source view license Current browse context: quant-ph new | recent | 2026-01 Change to browse by: cond-mat cond-mat.mtrl-sci cond-mat.supr-con References & Citations INSPIRE HEP NASA ADSGoogle Scholar Semantic Scholar export BibTeX citation Loading... BibTeX formatted citation × loading... Data provided by: Bookmark Bibliographic Tools Bibliographic and Citation Tools Bibliographic Explorer Toggle Bibliographic Explorer (What is the Explorer?) Connected Papers Toggle Connected Papers (What is Connected Papers?) Litmaps Toggle Litmaps (What is Litmaps?) scite.ai Toggle scite Smart Citations (What are Smart Citations?) Code, Data, Media Code, Data and Media Associated with this Article alphaXiv Toggle alphaXiv (What is alphaXiv?) Links to Code Toggle CatalyzeX Code Finder for Papers (What is CatalyzeX?) DagsHub Toggle DagsHub (What is DagsHub?) GotitPub Toggle Gotit.pub (What is GotitPub?) Huggingface Toggle Hugging Face (What is Huggingface?) Links to Code Toggle Papers with Code (What is Papers with Code?) ScienceCast Toggle ScienceCast (What is ScienceCast?) Demos Demos Replicate Toggle Replicate (What is Replicate?) Spaces Toggle Hugging Face Spaces (What is Spaces?) Spaces Toggle TXYZ.AI (What is TXYZ.AI?) Related Papers Recommenders and Search Tools Link to Influence Flower Influence Flower (What are Influence Flowers?) Core recommender toggle CORE Recommender (What is CORE?) Author Venue Institution Topic About arXivLabs arXivLabs: experimental projects with community collaborators arXivLabs is a framework that allows collaborators to develop and share new arXiv features directly on our website. Both individuals and organizations that work with arXivLabs have embraced and accepted our values of openness, community, excellence, and user data privacy. arXiv is committed to these values and only works with partners that adhere to them. Have an idea for a project that will add value for arXiv's community? Learn more about arXivLabs. Which authors of this paper are endorsers? | Disable MathJax (What is MathJax?)