Anisotropic magnetism and band evolution induced by ferromagnetic phase transition in titanium-based kagome ferromagnet SmTi_3Bi_4  

作　　者：Zhe Zheng Long Chen Xuecong Ji Ying Zhou Gexing Qu Mingzhe Hu Yaobo Huang Hongming Weng Tian Qian Gang Wang 

机构地区：[1]Beijing National Laboratory for Condensed Matter Physics,Institute of Physics,Chinese Academy of Sciences,Beijing 100190,China [2]University of Chinese Academy of Sciences,Beijing 100049,China [3]School of Physics and Engineering,Henan University of Science and Technology,Luoyang 471023,China [4]Shanghai Synchrotron Radiation Facility,Shanghai Advanced Research Institute,Chinese Academy of Sciences,Shanghai 201210,China [5]Songshan Lake Materials Laboratory,Dongguan 523808,China [6]CAS Center for Excellence in Topological Quantum Computation,Chinese Academy of Sciences,Beijing 100190,China

出　　处：《Science China(Physics,Mechanics & Astronomy)》2024年第6期137-145,共9页中国科学：物理学、力学、天文学（英文版）

基　　金：supported by the Synergetic Extreme Condition User Facility(SECUF);the National Key Research and Development Program of China(Grant Nos.2022YFA1403800,2022YFA1403900,and 2018YFE0202600);the National Natural Science Foundation of China(Grant Nos.U22A6005,51832010,11888101,11925408,11921004,and 12188101);the Informatization Plan of the Chinese Academy of Sciences(Grant No.CASWX2021SF-0102);the Strategic Priority Research Program of Chinese Academy of Sciences(Grant Nos.XDB33000000,and XDB28000000);the“Dreamline”beamline of Shanghai Synchrotron Radiation Facility(SSRF)。

摘　　要：Kagome magnets with diverse topological quantum responses are crucial for next-generation topological engineering.The anisotropic magnetism and band evolution induced by ferromagnetic phase transition(FMPT)is reported in a newly discovered titanium-based kagome ferromagnet Sm Ti3Bi4,which features a distorted Ti kagome lattice and Sm atomic zig-zag chains.Temperature-dependent resistivity,heat capacity,and magnetic susceptibility reveal a ferromagnetic ordering temperature Tc of23.2 K.A large magnetic anisotropy,observed by applying the magnetic field along three crystallographic axes,identifies the b axis as the easy axis.Angle-resolved photoemission spectroscopy with first-principles calculations unveils the characteristic kagome motif,including the Dirac point at the Fermi level and multiple van Hove singularities.Notably,a band splitting and gap closing attributed to FMPT is observed,originating from the exchange coupling between Sm 4 f local moments and itinerant electrons of the kagome Ti atoms,as well as the time-reversal symmetry breaking induced by the long-range ferromagnetic order.Considering the large in-plane magnetization and the evolution of electronic structure under the influence of ferromagnetic ordering,such materials promise to be a new platform for exploring the intricate electronic properties and magnetic phases based on the kagome lattice.

关 键 词：kagome lattice anisotropic magnetism band splitting ferromagnetic phase transition ARPES 

分 类 号：O469[理学—凝聚态物理]