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△ [16p-Z03-2] Investigation of Coherent Phonon in Bi at Low Temperature with X-ray Free Electron Laser

〇Yuya Kubota¹, Yoshikazu Tanaka¹, Tadashi Togashi^2,1, Tomio Ebisu¹, Kenji Tamasaku¹, Hitoshi Osawa², Tetsuya Wada³, Iwao Matsuda³, Makina Yabashi^1,2 (1.RIKEN, 2.JASRI, 3.ISSP)

Keywords:coherent phonon, X-ray free-electron laser, ultrafast XRD at low temperature

Bi is one of the typical materials showing the photo-induced coherent phonons. In addition to the A_1g phonon mode, the E_g phonon modes appear at low temperature. To understand the generation mechanism of the photo-induced coherent phonons, which has remained controversial, requires to observe atomic variations at low temperature. In this study, we succeeded in developing an equipment for time-resolved X-ray diffraction at low temperature, and directly observing the lattice dynamics in photo-induced Bi.