Observation of kagome-like bands in two-dimensional semiconducting Cr8Se12

Sisheng Duan; Jing-Yang You; Zhihao Cai; Jian Gou; Dong Li; Yu Li Huang; Xiaojiang Yu; Siew Lang Teo; Shuo Sun; Yihe Wang; Ming Lin; Chun Zhang; Baojie Feng; Andrew T S Wee; Wei Chen

doi:10.1038/s41467-024-53314-1

Observation of kagome-like bands in two-dimensional semiconducting Cr₈Se₁₂

Nat Commun. 2024 Oct 16;15(1):8940. doi: 10.1038/s41467-024-53314-1.

Authors

Sisheng Duan^#^{1

2}, Jing-Yang You^#¹, Zhihao Cai^#³, Jian Gou^#⁴, Dong Li³, Yu Li Huang⁵, Xiaojiang Yu⁶, Siew Lang Teo⁷, Shuo Sun^{1

8}, Yihe Wang^{2

5}, Ming Lin⁹, Chun Zhang¹, Baojie Feng¹⁰, Andrew T S Wee¹¹, Wei Chen^{12

13

14

15}

Affiliations

¹ Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore, Singapore.
² Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore, Singapore.
³ Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China; School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, China.
⁴ School of Physics, Zhejiang University, Hangzhou, China. [email protected].
⁵ Joint School of National University of Singapore and Tianjin University, International Campus of Tianjin University, Binhai New City, Fuzhou, China.
⁶ Singapore Synchrotron Light Source, National University of Singapore, 5 Research Link, Singapore, Singapore.
⁷ Institute of Materials Research and Engineering (IMRE), A*STAR (Agency for Science, Technology and Research), 2 Fusionopolis Way, Singapore, Singapore.
⁸ Department of Physics, Shanghai Key Laboratory of High Temperature Superconductors, Shanghai University, Shanghai, China.
⁹ Institute of Materials Research and Engineering (IMRE), A*STAR (Agency for Science, Technology and Research), 2 Fusionopolis Way, Singapore, Singapore. [email protected].
¹⁰ Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China; School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, China. [email protected].
¹¹ Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore, Singapore. [email protected].
¹² Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore, Singapore. [email protected].
¹³ Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore, Singapore. [email protected].
¹⁴ Joint School of National University of Singapore and Tianjin University, International Campus of Tianjin University, Binhai New City, Fuzhou, China. [email protected].
¹⁵ National University of Singapore (Suzhou) Research Institute, Suzhou, China. [email protected].

^# Contributed equally.

Abstract

The kagome lattice is a versatile platform for investigating correlated electronic states. However, its realization in two-dimensional (2D) semiconductors for tunable device applications is still challenging. An alternative strategy to create kagome-like bands is to realize a coloring-triangle (CT) lattice in semiconductors through a distortion of a modified triangular lattice. Here, we report the observation of low-energy kagome-like bands in a semiconducting 2D transition metal chalcogenide-Cr₈Se₁₂ with a thickness of 7 atomic layers-which exhibits a CT lattice and a bandgap of 0.8 eV. The Cr-deficient layer beneath the topmost Se-full layer is partially occupied with 2/3 occupancy, yielding a √3 × √3 Cr honeycomb network. Angle-resolved photoemission spectroscopy measurements and first-principles investigations reveal the surface kagome-like bands near the valence band maximum, which are attributed to topmost Se p_z orbitals modulated by the honeycomb Cr.

Abstract

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