Correlation between unconventional superconductivity and strange metallicity revealed by operando superfluid density measurements
Strange-metal behavior has been observed in superconductors ranging from cuprates to pressurized nickelates, but its relationship to unconventional superconductivity remains elusive. Here, we perform operando superfluid density measurements on ion-gated FeSe films. We observe a synchronized evolution of the superconducting condensate and the strange-metal phase with electron doping, from which a linear scaling between zero-temperature superfluid density and strange-metal resistivity coefficient is further established. The scaling also applies to different iron-based and cuprate superconductors despite their distinct electronic structures and pairing symmetries. Such a correlation can be reproduced in a theoretical calculation on the two-dimensional Yukawa-Sachdev-Ye-Kitaev model by considering a cooperative effect of quantum critical fluctuation and disorder. These findings suggest that a common mechanism may govern both the Cooper pair condensation and the normal-state strange metallicity in unconventional superconductors.
Authors
- Qiuyan Shi (ORCID: https://orcid.org/0009-0007-5568-4648)
- Mingyang Qin (ORCID: https://orcid.org/0000-0001-5341-7465)
- Jie Yuan (ORCID: https://orcid.org/0000-0002-9639-8273)
- Wenxin Cheng
- Subir Sachdev (ORCID: https://orcid.org/0000-0002-2432-7070)
- Tao Xiang (ORCID: https://orcid.org/0000-0001-5998-7338)
- Yangmu Li (ORCID: https://orcid.org/0000-0003-0886-2919)
- Xingyu Jiang (ORCID: https://orcid.org/0000-0002-5008-4703)
- Chenyuan Li (ORCID: https://orcid.org/0000-0001-8566-1462)
- Ruozhou Zhang
- Zhongxu Wei (ORCID: https://orcid.org/0000-0002-6032-3907)
- Zhanyi Zhao (ORCID: https://orcid.org/0000-0001-8116-9139)
- Kui Jin (ORCID: https://orcid.org/0000-0003-2208-8501)
- Xuewei Wang (ORCID: https://orcid.org/0000-0003-3679-7421)
- Qihong Chen (ORCID: https://orcid.org/0000-0002-6039-0456)
- Zi-Xiang Li
- Juan Xu (ORCID: https://orcid.org/0000-0003-3472-2055)
- Zhongxian Zhao
Institutions
- Harvard University (US)
- Chinese Academy of Sciences (CN)
- Fudan University (CN)
- Southern University of Science and Technology (CN)
- Songshan Lake Materials Laboratory (CN)
- Beijing Academy of Quantum Information Sciences (CN)
- Institute of Physics (CN)
- University of Chinese Academy of Sciences (CN)
- State Key Laboratory of Surface Physics
Publication Details
- Journal
- Science Advances
- Published
- 2025-08-22
- DOI
- https://doi.org/10.1126/sciadv.adu0795
- Citations
- 2
- Primary Topic
- Iron-based superconductors research
- Type
- article
- Field-Weighted Citation Impact
- 0.85