Orbital-selective effect of spin reorientation on the Dirac fermions in a non-charge-ordered kagome ferromagnet Fe3Ge

Rui Lou; Liqin Zhou; Wenhua Song; Alexander Fedorov; Zhijun Tu; Bei Jiang; Qi Wang; Man Li; Zhonghao Liu; Xuezhi Chen; Oliver Rader; Bernd Büchner; Yujie Sun; Hongming Weng; Hechang Lei; Shancai Wang

doi:10.1038/s41467-024-53343-w

Orbital-selective effect of spin reorientation on the Dirac fermions in a non-charge-ordered kagome ferromagnet Fe₃Ge

Nat Commun. 2024 Nov 13;15(1):9823. doi: 10.1038/s41467-024-53343-w.

Authors

Rui Lou^#^{1

2

3}, Liqin Zhou^#^{4

5}, Wenhua Song^#⁶, Alexander Fedorov^#^{7

8

9}, Zhijun Tu^#⁶, Bei Jiang^{4

5}, Qi Wang^{6

10

11}, Man Li¹², Zhonghao Liu¹³, Xuezhi Chen^{5

14}, Oliver Rader⁸, Bernd Büchner^{7

15}, Yujie Sun^{16

17

18}, Hongming Weng^{19

20

21}, Hechang Lei²², Shancai Wang²³

Affiliations

¹ Leibniz Institute for Solid State and Materials Research, IFW Dresden, 01069, Dresden, Sachsen, Germany. [email protected].
² Helmholtz-Zentrum Berlin für Materialien und Energie, Albert-Einstein-Straße 15, 12489, Berlin, Germany. [email protected].
³ Joint Laboratory "Functional Quantum Materials" at BESSY II, 12489, Berlin, Germany. [email protected].
⁴ Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China.
⁵ University of Chinese Academy of Sciences, Beijing, 100049, China.
⁶ Department of Physics, Key Laboratory of Quantum State Construction and Manipulation (Ministry of Education), and Beijing Key Laboratory of Opto-electronic Functional Materials & Micro-nano Devices, Renmin University of China, Beijing, 100872, China.
⁷ Leibniz Institute for Solid State and Materials Research, IFW Dresden, 01069, Dresden, Sachsen, Germany.
⁸ Helmholtz-Zentrum Berlin für Materialien und Energie, Albert-Einstein-Straße 15, 12489, Berlin, Germany.
⁹ Joint Laboratory "Functional Quantum Materials" at BESSY II, 12489, Berlin, Germany.
¹⁰ School of Physical Science and Technology, ShanghaiTech University, Shanghai, 201210, China.
¹¹ ShanghaiTech Laboratory for Topological Physics, ShanghaiTech University, Shanghai, 201210, China.
¹² School of Information Network Security, People's Public Security University of China, Beijing, 100038, China.
¹³ Institute of High-Pressure Physics and School of Physical Science and Technology, Ningbo University, Ningbo, 315211, China.
¹⁴ Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai, 201800, China.
¹⁵ Institute of Solid State and Materials Physics, TU Dresden, 01062, Dresden, Sachsen, Germany.
¹⁶ Department of Physics and Guangdong Basic Research Center of Excellence for Quantum Science, Southern University of Science and Technology (SUSTech), Shenzhen, 518055, China.
¹⁷ Quantum Science Center of Guangdong-Hong Kong-Macao Greater Bay Area (Guangdong), Shenzhen, 518045, China.
¹⁸ Institute of Advanced Science Facilities, Shenzhen, Guangdong, 518107, China.
¹⁹ Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China. [email protected].
²⁰ University of Chinese Academy of Sciences, Beijing, 100049, China. [email protected].
²¹ Songshan Lake Materials Laboratory, Dongguan, Guangdong, 523808, China. [email protected].
²² Department of Physics, Key Laboratory of Quantum State Construction and Manipulation (Ministry of Education), and Beijing Key Laboratory of Opto-electronic Functional Materials & Micro-nano Devices, Renmin University of China, Beijing, 100872, China. [email protected].
²³ Department of Physics, Key Laboratory of Quantum State Construction and Manipulation (Ministry of Education), and Beijing Key Laboratory of Opto-electronic Functional Materials & Micro-nano Devices, Renmin University of China, Beijing, 100872, China. [email protected].

^# Contributed equally.

PMID: 39537600
DOI: 10.1038/s41467-024-53343-w

Abstract

Kagome magnets provide a fascinating platform for the realization of correlated topological quantum phases under various magnetic ground states. However, the effect of the magnetic spin configurations on the characteristic electronic structure of the kagome-lattice layer remains elusive. Here, utilizing angle-resolved photoemission spectroscopy and density functional theory calculations, we report the spectroscopic evidence for the spin-reorientation effect of a kagome ferromagnet Fe₃Ge, which is composed solely of kagome planes. As the Fe moments cant from the c-axis into the ab plane upon cooling, the two kinds of kagome-derived Dirac fermions respond quite differently. The one with less-dispersive bands (k_z ~ 0) containing the $3 d_{z^{2}}$ orbitals evolves from gapped into nearly gapless, while the other with linear dispersions (k_z ~ π) embracing the 3d_xz/3d_yz components remains intact, suggesting that the effect of spin reorientation on the Dirac fermions has an orbital selectivity. Moreover, we demonstrate that there is no signature of charge order formation in Fe₃Ge, contrasting with its sibling compound FeGe, a newly established charge-density-wave kagome magnet.