摘要
The simple kagome-lattice band structure possesses Dirac cones,flat band,and saddle point with van Hove singularities in the electronic density of states,facilitating the emergence of various electronic orders.Here we report a titanium-based kagome metal CsTi_(3)Bi_(5)where titanium atoms form a kagome network,resembling its isostructural compound CsV_3Sb_5.Thermodynamic properties including the magnetization,resistance,and heat capacity reveal the conventional Fermi liquid behavior in the kagome metal CsTi_(3)Bi_(5)and no signature of superconducting or charge density wave(CDW)transition anomaly down to 85 m K.Systematic angle-resolved photoemission spectroscopy measurements reveal multiple bands crossing the Fermi level,consistent with the first-principles calculations.The flat band formed by the destructive interference of hopping in the kagome lattice is observed directly.Compared to Cs V_(3)Sb_(5),the van Hove singularities are pushed far away above the Fermi level in CsTi_(3)Bi_(5),in line with the absence of CDW.Furthermore,the first-principles calculations identify the nontrivial Z_(2)topological properties for those bands crossing the Fermi level,accompanied by several local band inversions.Our results suppose CsTi_(3)Bi_(5)as a complementary platform to explore the superconductivity and nontrivial band topology.
作者
王渊
刘以轩
郝占阳
程文静
邓竣泽
王郁欣
顾雨豪
马小明
戎洪涛
张发远
郭抒
张成成
江志诚
杨逸尘
刘万领
姜琦
刘正太
叶茂
沈大伟
刘毅
崔胜涛
王乐
刘才
林君浩
刘影
蔡永青
朱金龙
陈朝宇
梅佳伟
Yuan Wang;Yixuan Liu;Zhanyang Hao;Wenjing Cheng;Junze Deng;Yuxin Wang;Yuhao Gu;Xiao-Ming Ma;Hongtao Rong;Fayuan Zhang;Shu Guo;Chengcheng Zhang;Zhicheng Jiang;Yichen Yang;Wanling Liu;Qi Jiang;Zhengtai Liu;Mao Ye;Dawei Shen;Yi Liu;Shengtao Cui;Le Wang;Cai Liu;Junhao Lin;Ying Liu;Yongqing Cai;Jinlong Zhu;Chaoyu Chen;Jia-Wei Mei(Shenzhen Institute for Quantum Science and Engineering(SIQSE)and Department of Physics,Southern University of Science and Technology(SUSTech),Shenzhen 518055,China;Beijing National Laboratory for Condensed Matter Physics,and Institute of Physics,Chinese Academy of Sciences,Beijing 100190,China;State Key Laboratory of Functional Materials for Informatics and Center for Excellence in Superconducting Electronics,Shanghai Institute of Microsystem and Information Technology,Chinese Academy of Sciences,Shanghai 200050,China;National Synchrotron Radiation Laboratory,University of Science and Technology of China,Hefei 230029,China)
基金
the National Key R&D Program of China(Grant No.2022YFA1403700)
the National Natural Science Foundation of China(Grant Nos.12074163 and 12004030)
the Guangdong Basic and Applied Basic Research Foundation(Grant Nos.2022B1515020046,2022B1515130005,2021B1515130007,and 2020B1515120100)
the Guangdong Innovative and Entrepreneurial Research Team Program(Grant Nos.2017ZT07C062 and 2019ZT08C044)
the Shenzhen Science and Technology Program(Grant No.KQTD20190929173815000)
Shenzhen Key Laboratory of Advanced Quantum Functional Materials and Devices(Grant No.ZDSYS20190902092905285)
the Shenzhen Fundamental Research Program(Grant No.JCYJ20220818100405013)
China Postdoctoral Science Foundation(Grant No.2020M682780 and 2022M711495)。
