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arXiv · 2212.04460

Tunable van Hove singularity without structural instability in Kagome metal CsTi$_3$Bi$_5$

Bo Liu·Minquan Kuang·Yang Luo·Yongkai Li·Linwei Huai·Shuting Peng·Zhiyuan Wei·Jianchang Shen·Bingqian Wang·Yu Miao·Xiupeng Sun·Zhipeng Ou·Yugui Yao·Zhiwei Wang·Junfeng He
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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.

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Bo Liu, Minquan Kuang, Yang Luo, Yongkai Li, Linwei Huai, Shuting Peng, Zhiyuan Wei, Jianchang Shen, Bingqian Wang, Yu Miao, Xiupeng Sun, Zhipeng Ou, Yugui Yao, Zhiwei Wang, Junfeng He. 2022-12-08. Tunable van Hove singularity without structural instability in Kagome metal CsTi$_3$Bi$_5$. https://doi.org/10.1103/physrevlett.131.026701

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