Researchers involving the University of Würzburg discover microscopic connection between correlated electron states and superconductivity. The study is published in Nature.
How exactly unconventional superconductivity arises is one of the central questions of modern solid-state physics. A new study published in the scientific journal Nature provides crucial insights into this question.
For the first time, an international research team was able to demonstrate a direct microscopic connection between a strongly correlated normal state and superconductivity in so-called moiré materials. In the long term, these findings could contribute to the development of new quantum materials and superconductors for future quantum technologies.
Professor Giorgio Sangiovanni from the Institute of Theoretical Physics and Astrophysics at Julius-Maximilians-Universität Würzburg (JMU) was involved in the study. His research is part of the Cluster of Excellence ctd.qmat - Complexity, Topology and Dynamics in Quantum Matter - at JMU and the Technical University of Dresden.
Novel quantum states and unconventional superconductivity
Moiré materials consist of atomically thin crystal layers that are stacked with a slight twist relative to each other.
This minimal twist fundamentally changes the behavior of the electrons: their mobility decreases, while their mutual interactions dominate. This gives rise to novel quantum states such as correlated insulators, magnetism, and unconventional superconductivity.
Until now, however, it was unclear exactly how superconductivity develops from these strongly correlated initial states. To clarify this, the researchers combined high-precision experiments using scanning tunneling microscopy with theoretical models. This enabled them to study twisted graphene systems, which allow particularly precise control over electronic interactions and symmetries.
The theoretical analysis of the data was carried out in close cooperation with partner institutions from Princeton, San Sebastián, Frankfurt and Hamburg at Professor Sangiovanni's chair.
New quantum materials and superconductors for future quantum technologies
The key finding: the superconductivity observed does not arise from an ordinary metal, but from an already strongly correlated state with broken symmetry.
Particularly noteworthy was the detection of a spiral-shaped order of the so-called "valley" degree of freedom. In addition, the researchers observed several energy gaps whose behavior varies with temperature and magnetic field - a clear indication of the close connection between the normal state and superconductivity.
The results provide a new physical understanding of how unconventional and possibly also high-temperature superconductivity arises. In the long term, the findings could contribute to the targeted development of new quantum materials and superconductors for future quantum technologies.
Cluster of Excellence ctd.qmat
The Cluster of Excellence ctd.qmat - Complexity, Topology and Dynamics in Quantum Matter - at Julius-Maximilians-Universität Würzburg and Technische Universität Dresden explores and develops novel quantum materials with tailored properties. Around 300 researchers from over 30 countries work at the interface of physics, chemistry, and materials science to lay the foundations for tomorrow's technologies. In 2026, the cluster entered the second funding period of the German Excellence Strategy of the Federal and State Governments - with an expanded focus on the dynamics of quantum processes.
Publication
Nature Hyunjin Kim, Gautam Rai, Lorenzo Crippa, Dumitru Călugăru, Haoyu Hu, Youngjoon Choi, Lingyuan Kong, Eli Baum, Yiran Zhang, Ludwig Holleis, Kenji Watanabe, Takashi Taniguchi, Andrea F. Young, B. Andrei Bernevig, Roser Valentí, Giorgio Sangiovanni, Tim Wehling, Stevan Nadj-Perge Resolving Intervalley Gaps and Many-Body Resonances in a Moiré Superconductor. Nature, 4 February 2026, DOI 10.1038/s41586-025-10067-1
