NMR Evidence for Universal Pseudogap Behavior in Quasi-Two-Dimensional FeSe-Based Superconductors  

作　　者：B.L.Kang M.Z.Shi D.Zhao S.J.Li J.Li L.X.Zheng D.W.Song L.P.Nie T.Wu X.H.Chen 康宝蕾;石孟竹;赵丹;李顺姣;李建;郑立玄;宋殿武;聂林鹏;吴涛;陈仙辉(Hefei National Research Center for Physical Sciences at the Microscale,University of Science and Technology of China,Hefei 230026,China;Key Laboratory of Strongly coupled Quantum Matter Physics,Department of Physics,University of Science and Technology of China,Hefei 230026,China;CAS Center for Excellence in Superconducting Electronics(CENSE),Shanghai 200050,China;Collaborative Innovation Center of Advanced Microstructures,Nanjing University,Nanjing 210093,China;Hefei National Laboratory,University of Science and Technology of China,Hefei 230088,China)

机构地区：[1]Hefei National Research Center for Physical Sciences at the Microscale,University of Science and Technology of China,Hefei 230026,China [2]Key Laboratory of Strongly coupled Quantum Matter Physics,Department of Physics,University of Science and Technology of China,Hefei 230026,China [3]CAS Center for Excellence in Superconducting Electronics(CENSE),Shanghai 200050,China [4]4Collaborative Innovation Center of Advanced Microstructures,Nanjing University,Nanjing 210093,China [5]Hefei National Laboratory,University of Science and Technology of China,Hefei 230088,China

出　　处：《Chinese Physics Letters》2022年第12期71-76,共6页中国物理快报（英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant Nos.11888101 and 12034004);the National Key R&D Program of China(Grant No.2017YFA0303000);the Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDB25000000);the Anhui Initiative in Quantum Information Technologies(Grant No.AHY160000);the Innovation Program for Quantum Science and Technology(Grant No.2021ZD0302800)。

摘　　要：Recently,by intercalating organic ions into bulk FeSe superconductors,two kinds of layered FeSe-based superconductors[(TBA)xFeSe and(CTA)xFeSe]with superconducting transition temperatures(Tc)above 40 K have been discovered.Due to the large interlayer distance(~15A),these new layered superconductors have a large resistivity anisotropy analogous to bismuth-based cuprate superconductors.Moreover,remarkable pseudogap behavior well above Tcis revealed by nuclear magnetic resonance(NMR)measurements on77Se nuclei,suggesting a preformed pairing scenario similar to that of cuprates.Here,we report another new kind of organic-ion-intercalated FeSe superconductor,(PY)xFeSe,with a reduced interlayer distance(~10A)compared to(TBA)xFeSe and(CTA)xFeSe.By performing77Se NMR and transport measurements,we observe a similar pseudogap behavior well above Tcof~40 K and a large resistivity anisotropy of~10~4 in(PY)xFeSe.All these facts strongly support a universal pseudogap behavior in these layered FeSe-based superconductors with quasi-two-dimensional electronic structures.

关 键 词：NMR SUPERCONDUCTORS LAYERED 

分 类 号：O469[理学—凝聚态物理]