Tunable Van Hove Singularity without Structural Instability in Kagome Metal CsTi_{3}Bi_{5}

Bo Liu; Min-Quan Kuang; Yang Luo; Yongkai Li; Cheng Hu; Jiarui Liu; Qian Xiao; Xiquan Zheng; Linwei Huai; Shuting Peng; Zhiyuan Wei; Jianchang Shen; Bingqian Wang; Yu Miao; Xiupeng Sun; Zhipeng Ou; Shengtao Cui; Zhe Sun; Makoto Hashimoto; Donghui Lu; Chris Jozwiak; Aaron Bostwick; Eli Rotenberg; Luca Moreschini; Alessandra Lanzara; Yao Wang; Yingying Peng; Yugui Yao; Zhiwei Wang; Junfeng He

doi:10.1103/PhysRevLett.131.026701

Tunable Van Hove Singularity without Structural Instability in Kagome Metal CsTi_{3}Bi_{5}

Phys Rev Lett. 2023 Jul 14;131(2):026701. doi: 10.1103/PhysRevLett.131.026701.

Authors

Bo Liu¹, Min-Quan Kuang², Yang Luo¹, Yongkai Li^{3

4}, Cheng Hu⁵, Jiarui Liu^{1

6}, Qian Xiao⁷, Xiquan Zheng⁷, Linwei Huai¹, Shuting Peng¹, Zhiyuan Wei¹, Jianchang Shen¹, Bingqian Wang¹, Yu Miao¹, Xiupeng Sun¹, Zhipeng Ou¹, Shengtao Cui⁸, Zhe Sun⁸, Makoto Hashimoto⁹, Donghui Lu⁹, Chris Jozwiak¹⁰, Aaron Bostwick¹⁰, Eli Rotenberg¹⁰, Luca Moreschini^{5

11}, Alessandra Lanzara^{5

11}, Yao Wang⁶, Yingying Peng⁷, Yugui Yao^{3

4}, Zhiwei Wang^{3

4

12}, Junfeng He¹

Affiliations

¹ Department of Physics and CAS Key Laboratory of Strongly-coupled Quantum Matter Physics, University of Science and Technology of China, Hefei, Anhui 230026, China.
² Chongqing Key Laboratory of Micro & Nano Structure Optoelectronics, and School of Physical Science and Technology, Southwest University, Chongqing 400715, China.
³ Centre for Quantum Physics, Key Laboratory of Advanced Optoelectronic Quantum Architecture and Measurement (MOE), School of Physics, Beijing Institute of Technology, Beijing 100081, China.
⁴ Beijing Key Lab of Nanophotonics and Ultrafine Optoelectronic Systems, Beijing Institute of Technology, Beijing 100081, China.
⁵ Material Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
⁶ Department of Physics and Astronomy, Clemson University, Clemson, South Carolina 29631, USA.
⁷ International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China.
⁸ National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, Anhui 230026, China.
⁹ Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA.
¹⁰ Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
¹¹ Department of Physics, University of California, Berkeley, Berkeley, California 94720, USA.
¹² Material Science Center, Yangtze Delta Region Academy of Beijing Institute of Technology, Jiaxing 314011, China.

PMID: 37505968
DOI: 10.1103/PhysRevLett.131.026701

Abstract

In kagome metal CsV_{3}Sb_{5}, multiple intertwined orders are accompanied by both electronic and structural instabilities. These exotic orders have attracted much recent attention, but their origins remain elusive. The newly discovered CsTi_{3}Bi_{5} is a Ti-based kagome metal to parallel CsV_{3}Sb_{5}. Here, we report angle-resolved photoemission experiments and first-principles calculations on pristine and Cs-doped CsTi_{3}Bi_{5} samples. Our results reveal that the van Hove singularity (vHS) in CsTi_{3}Bi_{5} can be tuned in a large energy range without structural instability, different from that in CsV_{3}Sb_{5}. As such, CsTi_{3}Bi_{5} provides a complementary platform to disentangle and investigate the electronic instability with a tunable vHS in kagome metals.