Emergent superconducting fluctuations in compressed kagome superconductor CsV_(3)Sb_(5)  

作　　者：Xikai Wen Fanghang Yu Zhigang Gui Yuqing Zhang Xingyuan Hou Lei Shan Tao Wu Ziji Xiang Zhenyu Wang Jianjun Ying Xianhui Chen 

机构地区：[1]Department of Physics,and CAS Key Laboratory of Strongly-coupled Quantum Matter Physics,University of Science and Technology of China,Hefei 230026,China [2]CAS Center for Excellence in Quantum Information and Quantum Physics,Hefei 230026,China [3]Information Materials and Intelligent Sensing Laboratory of Anhui Province,Institutes of Physical Science and Information Technology,Anhui University,Hefei 230601,China [4]Key Laboratory of Structure and Functional Regulation of Hybrid Materials of Ministry of Education,Anhui University,Hefei 230601,China

出　　处：《Science Bulletin》2023年第3期259-265,M0003,共8页科学通报（英文版）

基　　金：supported by the National Natural Science Foundation of China(11888101 and 11534010);the National Key Research and Development Program of the Ministry of Science and Technology of China(2017YFA0303001 and 2019YFA0704900);the Anhui Initiative in Quantum Information Technologies(AHY160000);the Science Challenge Project of China(TZ2016004);the Key Research Program of Frontier Sciences,CAS,China(QYZDYSSWSLH021);the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB25000000);the Collaborative Innovation Program of Hefei Science Center,CAS(2020HSC-CIP014);the Fundamental Research Funds for the Central Universities(WK3510000011).

摘　　要：The recent discovery of superconductivity(SC)and charge density wave(CDW)in kagome metals AV3Sb5(A=K,Rb,Cs)provides an ideal playground for the study of emergent electronic orders.Application of moderate pressure leads to a two-dome-shaped SC phase regime in CsV_(3)Sb_(5) accompanied by the destabilizing of CDW phase.Nonetheless,the nature of this pressure-tuned SC state and its interplay with the CDW are yet to be explored.Here,we perform soft point-contact spectroscopy(SPCS)measurements in CsV_(3)Sb_(5) to investigate the evolution of superconducting order parameter with pressure.Surprisingly,we find that the superconducting gap is significantly enhanced between the two SC domes,at which the zero-resistance temperature is suppressed and the transition is remarkably broadened.Moreover,the temperature-dependence of the SC gap in this pressure range severely deviates from the conventional Bardeen-Cooper-Schrieffer(BCS)behavior,evidencing for strong Cooper pair phase fluctuations.These findings reveal the complex intertwining of the CDW with SC in the compressed CsV_(3)Sb_(5),suggesting striking parallel to the cuprate superconductor La2
xBaxCuO4.Our results point to the essential role of charge degree of freedom in the development of intertwining electronic orders,and thus provide new constraints for theories.

关 键 词：Kagome superconductor Superconducting fluctuations Charge density wave 

分 类 号：O413[理学—理论物理]