Ultrafast x-ray scattering reveals composite amplitude collective mode in the Weyl charge density wave material (TaSe$_4$)$_2$I

Quynh L. Nguyen; Ryan A. Duncan; Gal Orenstein; Yijing Huang; Viktor Krapivin; Gilberto de la Pena; Chance Ornelas-Skarin; David A. Reis; Peter Abbamonte; Simon Bettler; Matthieu Chollet; Matthias C. Hoffmann; Matthew Hurley; Soyeun Kim; Patrick S. Kirchmann; Yuya Kubota; Fahad Mahmood; Alexander Miller; Taito Osaka; Kejian Qu; Takahiro Sato; Daniel P. Shoemaker; Nicholas Sirica; Sanghoon Song; Jade Stanton; Samuel W. Teitelbaum; Sean E. Tilton; Tadashi Togashi; Diling Zhu; Mariano Trigo

arXiv · 2210.17483

Ultrafast x-ray scattering reveals composite amplitude collective mode in the Weyl charge density wave material (TaSe$_4$)$_2$I

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Abstract

We report ultrafast x-ray scattering experiments of the quasi-1D charge density wave (CDW) material (TaSe$_4$)$_2$I following photoexcitation with femtosecond infrared laser pulses. From the time-dependent diffraction signal at the CDW sidebands we identify an amplitude mode derived primarily from the transverse acoustic component of the CDW static distortion. The dynamics of this acoustic amplitude mode are described well by a model of a displacive excitation, which we interpret as mediated through a coupling to the optical phonon component associated with the tetramerization of the Ta chains.

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Quynh L. Nguyen, Ryan A. Duncan, Gal Orenstein, Yijing Huang, Viktor Krapivin, Gilberto de la Pena, Chance Ornelas-Skarin, David A. Reis, Peter Abbamonte, Simon Bettler, Matthieu Chollet, Matthias C. Hoffmann, Matthew Hurley, Soyeun Kim, Patrick S. Kirchmann, Yuya Kubota, Fahad Mahmood, Alexander Miller, Taito Osaka, Kejian Qu, Takahiro Sato, Daniel P. Shoemaker, Nicholas Sirica, Sanghoon Song, Jade Stanton, Samuel W. Teitelbaum, Sean E. Tilton, Tadashi Togashi, Diling Zhu, Mariano Trigo. 2022-12-23. Ultrafast x-ray scattering reveals composite amplitude collective mode in the Weyl charge density wave material (TaSe$_4$)$_2$I. https://arxiv.org/abs/2210.17483

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