Quantum Sensing of Copper-Phthalocyanine Electron Spins via NV Relaxometry

Quantum Physics arXiv:2511.03200 (quant-ph) [Submitted on 5 Nov 2025] Title:Quantum Sensing of Copper-Phthalocyanine Electron Spins via NV Relaxometry Authors:Boning Li, Xufan Li, Yifan Quan, Avetik R Harutyunyan, Paola Cappellaro View a PDF of the paper titled Quantum Sensing of Copper-Phthalocyanine Electron Spins via NV Relaxometry, by Boning Li and 4 other authors View PDF HTML (experimental) Abstract:Molecular spin systems are promising candidates for quantum information processing and nanoscale sensing, yet their characterization at room temperature remains challenging due to fast spin decoherence. In this work, we use $T_1$ relaxometry of shallow nitrogen-vacancy (NV) centers in diamond to probe the electron spin ensemble of a polycrystalline copper phthalocyanine (CuPc) thin film. In addition to unequivocally identifying the NV-CuPc interaction thanks to its hyperfine spectrum, we further extract key parameters of the CuPc spin ensemble, including its correlation time and local lattice orientation, that cannot be measured in bulk electron resonance experiments. The analysis of our experimental results confirms that electron-electron interactions dominate the decoherence dynamics of CuPc at room temperature. Additionally, we demonstrate that the CuPc-enhanced NV relaxometry can serve as a robust method to estimate the NV depth with $\sim1$~nm precision. Our results establish NV centers as powerful probes for molecular spin systems, providing insights into molecular qubits, spin bath engineering, and hybrid quantum materials, and offering a potential pathway toward their applications such as molecular-scale quantum processors and spin-based quantum networks. Subjects: Quantum Physics (quant-ph); Chemical Physics (physics.chem-ph) Cite as: arXiv:2511.03200 [quant-ph] (or arXiv:2511.03200v1 [quant-ph] for this version) https://doi.org/10.48550/arXiv.2511.03200 Focus to learn more arXiv-issued DOI via DataCite (pending registration) Submission history From: Boning Li [view email] [v1] Wed, 5 Nov 2025 05:33:13 UTC (6,273 KB) Full-text links: Access Paper: View a PDF of the paper titled Quantum Sensing of Copper-Phthalocyanine Electron Spins via NV Relaxometry, by Boning Li and 4 other authorsView PDFHTML (experimental)TeX Source view license Current browse context: quant-ph new | recent | 2025-11 Change to browse by: physics physics.chem-ph 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?)