[19p-A25-1~15] 3.5 Ultrashort-pulse and high-intensity lasers

1:45 PM - 2:00 PM JST(4:45 AM - 5:00 AM UTC)Presentation by Applicant for JSAP Young Scientists Presentation Award

[19p-A25-2] Higher-order phonon frequency generations in an optical response of two-dimensional layered semiconductors

〇(P)Takumi Fukuda^1,2, Kotaro Makino³, Yuta Saito⁴, Paul Fons⁵, Ryo Ishikawa⁶, Keiji Ueno⁶, Muneaki Hase² (1.OIST, 2.Univ. Tsukuba, 3.AIST, 4.Tohoku Univ., 5.Keio Univ., 6.Saitama Univ.)

Keywords:

transition-metal dichalcogenide,coherent phonon,ultrafast spectroscopy

We focus on the 2D layered semiconductor 2H-MoTe₂ and investigate the optical response in the ultrafast quasiparticle dynamics of carriers and phonons under photoexcitation. We observed long-lived out-of-plane coherent optical phonons that oscillate for more than 20 ps. Additionally, we explain the physical mechanisms behind generating higher-order phonon frequencies observed in the early time region (< 1 ps) immediately after photoexcitation.