Ultrafast dynamics of the low frequency shear phonon in 1T′- MoTe 2

Takumi Fukuda, Kotaro Makino, Yuta Saito, Paul Fons, Alexander V. Kolobov, Keiji Ueno, Muneaki Hase

研究成果: Article査読

8 被引用数 (Scopus)

抄録

We report on the dynamics of coherent phonons in semimetal 1T′- MoTe 2 using femtosecond pump-probe spectroscopy. On an ultrafast sub-picosecond timescale at room temperature, a low frequency and long-lifetime shear phonon mode was observed at 0.39 THz, which was previously reported in the form of a characteristic phonon only in the low temperature T d - MoTe 2 phase. Unlike the other optical phonon modes, the shear phonon mode was found to strongly couple with photoexcited carriers. Moreover, the amplitude of the shear mode surprisingly decreased with increasing excitation density, a phenomenon that can be attributed to be a consequence of the lattice temperature increasing after excitation. These results provide useful physical information on ultrafast lattice symmetry switching between the normal semimetal 1T′ and the lattice inversion symmetry breaking Type-II Weyl semimetal T d phases.

本文言語English
論文番号093103
ジャーナルApplied Physics Letters
116
9
DOI
出版ステータスPublished - 2020 3月 2
外部発表はい

ASJC Scopus subject areas

  • 物理学および天文学(その他)

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