Correlation between unconventional superconductivity and strange metallicity revealed by operando superfluid density measurements

• DOI: 10.48550/arxiv.2409.18515
• Publication Date: 2024-09-27
• Authors: Ruozhou Zhang; Mingyang Qin; Chenyuan Li; Zhanyi Zhao; Zhongxu Wei; Juan Xu; Xingyu Jiang; Wenxin Cheng; Qiuyan Shi; Xuewei Wang; Jie Yuan; Yangmu Li; Qihong Chen; Tao Xiang; Subir Sachdev; Zi-Xiang Li; Kui Jin; Zhongxian Zhao
• Keywords: Superconductivity (cond-mat.supr-con); Condensed Matter - Strongly Correlated Electrons; Strongly Correlated Electrons (cond-mat.str-el); Condensed Matter - Superconductivity; FOS: Physical sciences

Strange-metal behavior has been observed in superconductors ranging from cuprates to pressurized nickelates, but its relationship unconventional superconductivity remains elusive. Here, we perform operando superfluid density measurements on ion-gated FeSe films. We observe for the first time a synchronized evolution of superconducting condensate and strange-metal phase with electron doping. A linear scaling between zero-temperature resistivity coefficient is further established, which nails down direct link formation state scattering carriers normal state. Remarkably, also applies different iron-based cuprate despite their distinct electronic structures pairing symmetries. Such correlation can be reproduced theoretical calculation two-dimensional Yukawa-Sachdev-Ye-Kitaev model by considering cooperative effect quantum critical fluctuation disorder. These findings indicate fundamental principle governing condensation superconductors.