Article Strongly Hybridized Phonons in One-Dimensional van der Waals Crystals

Shaoqi Sun ; Qingyun Lin ; Yihuan Li ; Daichi Kozawa SAMURAI ORCID (National Institute for Materials Science) ; Huizhen Wu ; Shigeo Maruyama ; Pilkyung Moon ; Toshikaze Kariyado SAMURAI ORCID (National Institute for Materials Science) ; Ryo Kitaura SAMURAI ORCID (National Institute for Materials Science) ; Sihan Zhao

2408.08596v2.pdf
Download file (6.17 MB)
Download as zip (5.93 MB)
Collection

Citation
Shaoqi Sun, Qingyun Lin, Yihuan Li, Daichi Kozawa, Huizhen Wu, Shigeo Maruyama, Pilkyung Moon, Toshikaze Kariyado, Ryo Kitaura, Sihan Zhao. Strongly Hybridized Phonons in One-Dimensional van der Waals Crystals. Physical Review Letters. 2025, 134 (17), 176101. https://doi.org/10.1103/PhysRevLett.134.176101

Description:

(abstract)

The phenomena of pronounced electron-electron and electron-phonon interactions in one-dimensional (1D) systems are ubiquitous, which are well described by frameworks of Luttinger liquid, Peierls instability, and concomitant charge density wave. However, the experimental observation of strongly hybridized phonons in 1D was not demonstrated. Herein we report the first observation of strongly hybridized phonons in 1D condensed matters by using double-walled carbon nanotubes (DWNTs), representative 1D van der Waals crystals, by combining the spectroscopic and microscopic tools as well as the ab initio density functional theory (DFT) calculations. We observe uncharted phonon modes in one commensurate and three incommensurate DWNT crystals, three of which concurrently exhibit strongly reconstructed electronic band structures. Our DFT calculations for the experimentally observed commensurate DWNT (7, 7) @ (12, 12) reveal that this new phonon mode originates from a (nearly) degenerate coupling between two transverse acoustic modes (ZA modes) of constituent inner and outer nanotubes having approximately trigonal and pentagonal rotational symmetry along the nanotube circumferences. Such coupling strongly hybridizes the two phonon modes in different shells and leads to the formation of a unique lattice motion featuring evenly distributed vibrational amplitudes over inner and outer nanotubes, distinct from any known phonon modes in 1D systems. All four DWNTs that exhibit the pronounced new phonon modes show small chiral angle twists, closely matched diameter ratios of 3/5 and decreased frequencies of new phonon modes with increased diameters, all supporting the uncovered coupling mechanism. Our discovery of strongly hybridized phonons in DWNTs opens new opportunities for engineering phonons and exploring novel phonon-related phenomena in 1D condensed matters.

Rights:

Keyword: phonon

Date published: 2025-04-28

Publisher: American Physical Society (APS)

Journal:

  • Physical Review Letters (ISSN: 10797114) vol. 134 issue. 17 176101

Funding:

  • National Key Research and Development Program of China 2022YFA1203400
  • National Key Research and Development Program of China 2023YFA1407900
  • National Natural Science Foundation of China 12174335
  • National Natural Science Foundation of China 12074260
  • Natural Science Foundation of Zhejiang Province LR23A040002
  • Japan Society for the Promotion of Science JP24K06968
  • Japan Society for the Promotion of Science 23K23161
  • Japan Society for the Promotion of Science JP24H02218
  • Japan Society for the Promotion of Science JP23H05469
  • New York University Shanghai
  • NYU-ECNU Institute of Physics

Manuscript type: Author's version (Accepted manuscript)

MDR DOI: https://doi.org/10.48505/nims.6062

First published URL: https://doi.org/10.1103/PhysRevLett.134.176101

Related item:

Other identifier(s):

Contact agent:

Updated at: 2025-12-24 14:22:33 +0900

Published on MDR: 2025-12-24 16:20:30 +0900

Filename Size
Filename 2408.08596v2.pdf (Thumbnail)
application/pdf 		Size 6.17 MB Detail