中国物理B ›› 2023, Vol. 32 ›› Issue (7): 77401-077401.doi: 10.1088/1674-1056/acca0e

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Multiple surface states, nontrivial band topology, and antiferromagnetism in GdAuAl4Ge2

Chengcheng Zhang(张成成)1, Yuan Wang(王渊)1, Fayuan Zhang(张发远)1, Hongtao Rong(戎洪涛)1, Yongqing Cai(蔡永青)1, Le Wang(王乐)1, Xiao-Ming Ma(马小明)1, Shu Guo(郭抒)1, Zhongjia Chen(陈仲佳)2,3, Yanan Wang(王亚南)2,3, Zhicheng Jiang(江志诚)4, Yichen Yang(杨逸尘)4, Zhengtai Liu(刘正太)4, Mao Ye(叶茂)4, Junhao Lin(林君浩)1, Jiawei Mei(梅佳伟)1, Zhanyang Hao(郝占阳)1,†, Zijuan Xie(谢子娟)5,‡, and Chaoyu Chen(陈朝宇)1,§   

  1. 1 Shenzhen Institute for Quantum Science and Engineering(SIQSE) and Department of Physics, Southern University of Science and Technology(SUSTech), Shenzhen 518055, China;
    2 Songshan Lake Materials Laboratory, Dongguan 523000, China;
    3 Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China;
    4 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;
    5 International School of Microelectronics, Dongguan University of Technology, Dongguan 523000, China
  • 收稿日期:2023-03-23 修回日期:2023-04-04 接受日期:2023-04-04 出版日期:2023-06-15 发布日期:2023-06-28
  • 通讯作者: Zhanyang Hao, Zijuan Xie, Chaoyu Chen E-mail:11849277@mail.sustech.edu.cn;zjxie@dgut.edu.cn;chency@sustech.edu.cn
  • 基金资助:
    Project supported by the National Key Research and Development Program of China (Grant No. 2022YFA1403700), the National Natural Science Foundation of China (Grant No. 12074163), the Basic and Applied Basic Research Foundation of Guangdong Province, China (Grants Nos. 2022B1515020046, 2022B1515130005, and 2021B1515130007), the Innovative and Entrepreneurial Research Team Program of Guangdong Province, China (Grant Nos. 2019ZT08C044), and Shenzhen Science and Technology Program (Grant No. KQTD20190929173815000). C. C. acknowledges the assistance of SUSTech Core Research Facilities.

Multiple surface states, nontrivial band topology, and antiferromagnetism in GdAuAl4Ge2

Chengcheng Zhang(张成成)1, Yuan Wang(王渊)1, Fayuan Zhang(张发远)1, Hongtao Rong(戎洪涛)1, Yongqing Cai(蔡永青)1, Le Wang(王乐)1, Xiao-Ming Ma(马小明)1, Shu Guo(郭抒)1, Zhongjia Chen(陈仲佳)2,3, Yanan Wang(王亚南)2,3, Zhicheng Jiang(江志诚)4, Yichen Yang(杨逸尘)4, Zhengtai Liu(刘正太)4, Mao Ye(叶茂)4, Junhao Lin(林君浩)1, Jiawei Mei(梅佳伟)1, Zhanyang Hao(郝占阳)1,†, Zijuan Xie(谢子娟)5,‡, and Chaoyu Chen(陈朝宇)1,§   

  1. 1 Shenzhen Institute for Quantum Science and Engineering(SIQSE) and Department of Physics, Southern University of Science and Technology(SUSTech), Shenzhen 518055, China;
    2 Songshan Lake Materials Laboratory, Dongguan 523000, China;
    3 Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China;
    4 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;
    5 International School of Microelectronics, Dongguan University of Technology, Dongguan 523000, China
  • Received:2023-03-23 Revised:2023-04-04 Accepted:2023-04-04 Online:2023-06-15 Published:2023-06-28
  • Contact: Zhanyang Hao, Zijuan Xie, Chaoyu Chen E-mail:11849277@mail.sustech.edu.cn;zjxie@dgut.edu.cn;chency@sustech.edu.cn
  • Supported by:
    Project supported by the National Key Research and Development Program of China (Grant No. 2022YFA1403700), the National Natural Science Foundation of China (Grant No. 12074163), the Basic and Applied Basic Research Foundation of Guangdong Province, China (Grants Nos. 2022B1515020046, 2022B1515130005, and 2021B1515130007), the Innovative and Entrepreneurial Research Team Program of Guangdong Province, China (Grant Nos. 2019ZT08C044), and Shenzhen Science and Technology Program (Grant No. KQTD20190929173815000). C. C. acknowledges the assistance of SUSTech Core Research Facilities.

摘要: Magnetic topological states of matter provide a fertile playground for emerging topological physics and phenomena. The current main focus is on materials whose magnetism stems from 3d magnetic transition elements, e.g., MnBi$_{{2}}$Te$_{4}$, Fe$_{{3}}$Sn$_{{2}}$, and Co$_{3}$Sn$_{{2}}$S$_{2}$. In contrast, topological materials with the magnetism from rare earth elements remain largely unexplored. Here we report rare earth antiferromagnet GdAuAl$_{{4}}$Ge$_{{2}}$ as a candidate magnetic topological metal. Angle resolved photoemission spectroscopy (ARPES) and first-principles calculations have revealed multiple bulk bands crossing the Fermi level and pairs of low energy surface states. According to the parity and Wannier charge center analyses, these bulk bands possess nontrivial $Z_{{2}}$ topology, establishing a strong topological insulator state in the nonmagnetic phase. Furthermore, the surface band pairs exhibit strong termination dependence which provides insight into their origin. Our results suggest GdAuAl$_{{4}}$Ge$_{2}$ as a rare earth platform to explore the interplay between band topology, magnetism and f electron correlation, calling for further study targeting on its magnetic structure, magnetic topology state, transport behavior, and microscopic properties.

关键词: magnetic topological material, surface state, ARPES, topological invariant

Abstract: Magnetic topological states of matter provide a fertile playground for emerging topological physics and phenomena. The current main focus is on materials whose magnetism stems from 3d magnetic transition elements, e.g., MnBi$_{{2}}$Te$_{4}$, Fe$_{{3}}$Sn$_{{2}}$, and Co$_{3}$Sn$_{{2}}$S$_{2}$. In contrast, topological materials with the magnetism from rare earth elements remain largely unexplored. Here we report rare earth antiferromagnet GdAuAl$_{{4}}$Ge$_{{2}}$ as a candidate magnetic topological metal. Angle resolved photoemission spectroscopy (ARPES) and first-principles calculations have revealed multiple bulk bands crossing the Fermi level and pairs of low energy surface states. According to the parity and Wannier charge center analyses, these bulk bands possess nontrivial $Z_{{2}}$ topology, establishing a strong topological insulator state in the nonmagnetic phase. Furthermore, the surface band pairs exhibit strong termination dependence which provides insight into their origin. Our results suggest GdAuAl$_{{4}}$Ge$_{2}$ as a rare earth platform to explore the interplay between band topology, magnetism and f electron correlation, calling for further study targeting on its magnetic structure, magnetic topology state, transport behavior, and microscopic properties.

Key words: magnetic topological material, surface state, ARPES, topological invariant

中图分类号:  (Electronic structure (photoemission, etc.))

  • 74.25.Jb
71.20.-b (Electron density of states and band structure of crystalline solids) 71.18.+y (Fermi surface: calculations and measurements; effective mass, g factor) 73.20.At (Surface states, band structure, electron density of states)