Correlation between unconventional superconductivity and strange metallicity revealed by operando superfluid density measurements
Year: 2025
Type: article
Abstract: 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.
Source: Science Advances
Institutions: Chinese Academy of Sciences, Fudan University, Institute of Physics, State Key Laboratory of Surface Physics, Southern University of Science and Technology, Harvard University, Songshan Lake Materials Laboratory, University of Chinese Academy of Sciences, Beijing Academy of Quantum Information Sciences
Language: English
Field: Materials Science
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $4,500
OpenAlex ID: W4413419004