摘要
In this study,Kagome superconductors,i.e.,CsV_(3)Sb_(5)single crystals and its Ta-doped variant,Cs(V_(0.86)Ta_(0.14))_(3)Sb_(5),were studied in detail via specific heat measurements.Results revealed that the charge density wave(CDW)was suppressed and the superconducting transition temperature(Tc)considerably increased from 2.8 to 4.6K upon Ta doping.The electronic specific heat of CsV_(3)Sb_(5)was fitted with a model comprising an s-wave gap and a highly anisotropic extended s-wave gap,where 2Δ/kBTc was smaller than the weak coupling limit of 3.5.Cs(V_(0.86)Ta_(0.14))_(3)Sb_(5) exhibited two isotropic s-wave gaps and yielded a larger gap of 2Δ/kBTc=5.04,indicating a significant enhancement in superconducting coupling.This evolution was attributed to the increased density of states near the Fermi level released by CDW gap suppression.These findings demonstrated that Ta doping enhanced superconducting coupling and variation of gap structure in CsV_(3)Sb_(5).
作者
Yiwen Li
Zhengyan Zhu
Qing Li
Yongze Ye
Zhiwei Wang
Yugui Yao
Hai-Hu Wen
李易文;朱政彦;李庆;叶永泽;王秩伟;姚裕贵;闻海虎(National Laboratory of Solid State Microstructures and Department of Physics,Collaborative Innovation Center of Advanced Microstructures,Nanjing University,Nanjing 210093,China;Key Laboratory of Advanced Optoelectronic Quantum Architecture and Measurement,Ministry of Education,School of Physics,Beijing Institute of Technology,Beijing 100081,China;Micronano Center,Beijing Key Lab of Nanophotonics and Ultrafine Optoelectronic Systems,Beijing Institute of Technology,Beijing 100081,China;Material Science Center,Yangtze Delta Region Academy of Beijing Institute of Technology,Jiaxing 314011,China)
基金
National Key R&D Program of China(Grant Nos.2022YFA1403201,2022YFA1403400,and 2020YFA0308800)
National Natural Science Foundation of China(Grant Nos.11927809,12061131001,11974171,92065109,and 12204231)
Fundamental Research Funds for the Central Universities(Grant No.020414380208).
