Phonon promoted charge density wave in topological kagome metal ScV6Sn6

Yong Hu; Junzhang Ma; Yinxiang Li; Yuxiao Jiang; Dariusz Jakub Gawryluk; Tianchen Hu; Jérémie Teyssier; Volodymyr Multian; Zhouyi Yin; Shuxiang Xu; Soohyeon Shin; Igor Plokhikh; Xinloong Han; Nicholas C Plumb; Yang Liu; Jia-Xin Yin; Zurab Guguchia; Yue Zhao; Andreas P Schnyder; Xianxin Wu; Ekaterina Pomjakushina; M Zahid Hasan; Nanlin Wang; Ming Shi

doi:10.1038/s41467-024-45859-y

Phonon promoted charge density wave in topological kagome metal ScV₆Sn₆

Nat Commun. 2024 Feb 23;15(1):1658. doi: 10.1038/s41467-024-45859-y.

Authors

Yong Hu^#^{1

2}, Junzhang Ma^#^{3

4

5}, Yinxiang Li^#⁶, Yuxiao Jiang⁷, Dariusz Jakub Gawryluk⁸, Tianchen Hu⁹, Jérémie Teyssier¹⁰, Volodymyr Multian¹¹, Zhouyi Yin¹², Shuxiang Xu⁹, Soohyeon Shin⁸, Igor Plokhikh⁸, Xinloong Han¹³, Nicholas C Plumb¹⁴, Yang Liu¹⁵, Jia-Xin Yin¹⁶, Zurab Guguchia¹⁷, Yue Zhao¹², Andreas P Schnyder¹⁸, Xianxin Wu¹⁹, Ekaterina Pomjakushina⁸, M Zahid Hasan⁷, Nanlin Wang^{9

20

21}, Ming Shi^{22

23}

Affiliations

¹ Photon Science Division, Paul Scherrer Institut, CH-5232, Villigen PSI, Switzerland. [email protected].
² Center of Quantum Materials and Devices and Department of Applied Physics, Chongqing University, 401331, Chongqing, China. [email protected].
³ Department of Physics, City University of Hong Kong, Kowloon, Hong Kong, China.
⁴ City University of Hong Kong Shenzhen Research Institute, Shenzhen, China.
⁵ Hong Kong Institute for Advanced Study, City University of Hong Kong, Kowloon, Hong Kong, China.
⁶ College of Science, University of Shanghai for Science and Technology, 200093, Shanghai, China.
⁷ Laboratory for Topological Quantum Matter and Advanced Spectroscopy (B7), Department of Physics, Princeton University, Princeton, NJ, USA.
⁸ Laboratory for Multiscale Materials Experiments, Paul Scherrer Institut, CH-5232, Villigen PSI, Switzerland.
⁹ International Center for Quantum Materials, School of Physics, Peking University, 100871, Beijing, China.
¹⁰ Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211, Geneva 4, Switzerland.
¹¹ Advanced Materials Nonlinear Optical Diagnostics lab, Institute of Physics, NAS of Ukraine, 46 Nauky pr., 03028, Kyiv, Ukraine.
¹² Institute for Quantum Science and Engineering and Department of Physics, Southern University of Science and Technology of China, Shenzhen, Guangdong, 518055, China.
¹³ Kavli Institute for Theoretical Sciences, University of Chinese Academy of Sciences, 100190, Beijing, China.
¹⁴ Photon Science Division, Paul Scherrer Institut, CH-5232, Villigen PSI, Switzerland.
¹⁵ Center for Correlated Matter and Department of Physics, Zhejiang University, 310058, Hangzhou, China.
¹⁶ Department of physics, Southern University of Science and Technology, 518055, Shenzhen, Guangdong, China.
¹⁷ Laboratory for Muon Spin Spectroscopy, Paul Scherrer Institute, CH-5232, Villigen PSI, Switzerland.
¹⁸ Max-Planck-Institut für Festkörperforschung, Heisenbergstrasse 1, D-70569, Stuttgart, Germany.
¹⁹ CAS Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, Beijing, 100190, China. [email protected].
²⁰ Beijing Academy of Quantum Information Sciences, Beijing, 100913, China.
²¹ Collaborative Innovation Center of Quantum Matter, Beijing, 100871, China.
²² Photon Science Division, Paul Scherrer Institut, CH-5232, Villigen PSI, Switzerland. [email protected].
²³ Center for Correlated Matter and Department of Physics, Zhejiang University, 310058, Hangzhou, China. [email protected].

^# Contributed equally.

Abstract

Charge density wave (CDW) orders in vanadium-based kagome metals have recently received tremendous attention, yet their origin remains a topic of debate. The discovery of ScV₆Sn₆, a bilayer kagome metal featuring an intriguing [Formula: see text] CDW order, offers a novel platform to explore the underlying mechanism behind the unconventional CDW. Here, we combine high-resolution angle-resolved photoemission spectroscopy, Raman scattering and density functional theory to investigate the electronic structure and phonon modes of ScV₆Sn₆. We identify topologically nontrivial surface states and multiple van Hove singularities (VHSs) in the vicinity of the Fermi level, with one VHS aligning with the in-plane component of the CDW vector near the [Formula: see text] point. Additionally, Raman measurements indicate a strong electron-phonon coupling, as evidenced by a two-phonon mode and new emergent modes. Our findings highlight the fundamental role of lattice degrees of freedom in promoting the CDW in ScV₆Sn₆.