Optical control of crystal structures is a promising route to change physical properties including topological nature of a targeting material. Time-resolved X-ray diffraction measurements using the X-ray free-electron laser are performed to study the ultrafast lattice dynamics of VTe2, which shows a unique charge-density-wave (CDW) ordering coupled to the topological surface states as a first-order phase transition. A significant oscillation of the CDW amplitude mode is observed at a superlattice reflection as well as Bragg reflections. The frequency of the oscillation is independent of the fluence of the pumping laser, which is prominent to the CDW ordering of the first-order phase transition. Furthermore, the timescale of the photoinduced 1T′′ to 1T phase transition is independent of the period of the CDW amplitude mode.
@article{arxiv.2305.17329,
title = {Ultrafast Control of Crystal Structure in a Topological Charge-Density-Wave Material},
author = {Takeshi Suzuki and Yuya Kubota and Natsuki Mitsuishi and Shunsuke Akatsuka and Jumpei Koga and Masato Sakano and Satoru Masubuchi and Yoshikazu Tanaka and Tadashi Togashi and Hiroyuki Ohsumi and Kenji Tamasaku and Makina Yabashi and Hidefumi Takahashi and Shintaro Ishiwata and Tomoki Machida and Iwao Matsuda and Kyoko Ishizaka and Kozo Okazaki},
journal= {arXiv preprint arXiv:2305.17329},
year = {2023}
}