Fermi-level flat band in a kagome magnet

被引：12
作者：
T. Y. Yang
Q. Wan
J. P. Song
Z. Du
J. Tang
Z. W. Wang
N. C. Plumb
M. Radovic
G. W. Wang
G. Y. Wang
Z. Sun
Jia-Xin Yin
Z. H. Chen
Y. B. Huang
R. Yu
M. Shi
Y. M. Xiong
N. Xu
机构：
[1] Institute for Advanced Studies, Wuhan University, Wuhan
[2] Anhui Province Key Laboratory of Condensed Matter Physics at Extreme Conditions, High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei
[3] Department of Physics, School of Physics and Optoelectronics Engineering, Anhui University, Hefei
[4] School of Physics and Technology, Wuhan University, Wuhan
[5] Swiss Light Source, Paul Scherrer Institut, Villigen PSI
[6] Analytical and Testing Center, Chongqing University, Chongqing
[7] Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing
[8] National Synchrotron Radiation Laboratory, University of Science and Technology of China, Anhui, Hefei
[9] Laboratory for Quantum Emergence, Department of Physics, Southern University of Science and Technology, Guangdong, Shenzhen
[10] Shanghai Synchrotron Radiation Facility, Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai
[11] Hefei National Laboratory, Hefei
[12] Wuhan Institute of Quantum Technology, Wuhan
来源：
Quantum Frontiers | / 1卷 / 1期
基金：
中国国家自然科学基金;
关键词：
Angle-resolved photoemission spectroscopy; Band structure; Flat band; Kagome lattice;
D O I：
10.1007/s44214-022-00017-7
中图分类号：
学科分类号：
摘要：
The band structure in a kagome lattice can naturally exhibit flat band, Dirac cones, and van Hove singularity, enabling rich interplays between correlation and topology. However, the flat band is rarely detected just at the Fermi level in kagome materials, which would be crucial to realize emergent flat band physics. Here, combining angle-resolved photoemission spectroscopy, transport measurements and first-principles calculation, we observe a striking Fermi-level flat band in paramagnetic YCr6Ge6 as a typical signature of electronic kagome lattice. We explicitly unveil that orbital character plays an essential role to realize electronic kagome lattice in crystals with transition-metal kagome layers. We further engineer this material with magnetic rare earth elements to break the time-reversal symmetry of the Fermi-level kagome flat band. Our work establishes a Fermi-level flat band in a kagome magnet as an exciting quantum platform. © The Author(s) 2022.
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