Theory for Charge Density Wave and Orbital-Flux State in Antiferromagnetic Kagome Metal FeGe  

作　　者：马海洋 殷嘉鑫 M.Zahid Hasan 刘健鹏 Hai-Yang Ma;Jia-Xin Yin;MZahid Hasan;Jianpeng Liu(School of Physical Science and Technology,ShanghaiTech University,Shanghai 201210,China;ShanghaiTech Laboratory for Topological Physics,ShanghaiTech University,Shanghai 201210,China;Quantum Science Center of Guangdong-HongKong-Macao Greater Bay Area,Shenzhen 518045,China;Laboratory for Topological Quantum Matter and Advanced Spectroscopy(B7),Department of Physics,Princeton University,Princeton,New Jersey 08544,USA;Princeton Institute for Science and Technology of Materials,Princeton University,Princeton,New Jersey 08544,USA;Materials Sciences Division,Lawrence Berkeley National Laboratory,Berkeley,California 94720,USA;Liaoning Academy of Materials,Shenyang 110167,China)

机构地区：[1]School of Physical Science and Technology,ShanghaiTech University,Shanghai 201210,China [2]ShanghaiTech Laboratory for Topological Physics,ShanghaiTech University,Shanghai 201210,China [3]Quantum Science Center of Guangdong-HongKong-Macao Greater Bay Area,Shenzhen 518045,China [4]Laboratory for Topological Quantum Matter and Advanced Spectroscopy(B7),Department of Physics,Princeton University,Princeton,New Jersey 08544,USA [5]Princeton Institute for Science and Technology of Materials,Princeton University,Princeton,New Jersey 08544,USA [6]Materials Sciences Division,Lawrence Berkeley National Laboratory,Berkeley,California 94720,USA [7]Liaoning Academy of Materials,Shenyang 110167,China

出　　处：《Chinese Physics Letters》2024年第4期90-104,共15页中国物理快报（英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant No.12174257);the National Key R&D program of China(Grant No.2020YFA0309601);the Science and Technology Commission of the Shanghai Municipality(Grant No.21JC1405100);the Start-Up Grant of ShanghaiTech University。

摘　　要：We theoretically study the charge order and orbital magnetic properties of a new type of antiferromagnetic kagome metal FeGe.Based on first-principles density functional theory calculations,we study the electronic structures,Fermi-surface quantum fluctuations,as well as phonon properties of the antiferromagnetic kagome metal FeGe.It is found that charge density wave emerges in such a system due to a subtle cooperation between electron-electron interactions and electron–phonon couplings,which gives rise to an unusual scenario of interaction-triggered phonon instabilities,and eventually yields a charge density wave(CDW)state.We further show that,in the CDW phase,the ground-state current density distribution exhibits an intriguing star-of-David pattern,leading to flux density modulation.The orbital fluxes(or current loops)in this system emerge as a result of the subtle interplay between magnetism,lattice geometries,charge order,and spin-orbit coupling(SOC),which can be described by a simple,yet universal,tight-binding theory including a Kane-Mele-type SOC term and a magnetic exchange interaction.We further study the origin of the peculiar step-edge states in FeGe,which sheds light on the topological properties and correlation effects in this new type of kagome antiferromagnetic material.

关 键 词：interaction PHONON ORBITAL 

分 类 号：O469[理学—凝聚态物理]