K-point longitudinal acoustic phonons are responsible for ultrafast intervalley scattering in monolayer MoSe2

oleh: Soungmin Bae, Kana Matsumoto, Hannes Raebiger, Ken-ichi Shudo, Yong-Hoon Kim, Ørjan Sele Handegård, Tadaaki Nagao, Masahiro Kitajima, Yuji Sakai, Xiang Zhang, Robert Vajtai, Pulickel Ajayan, Junichiro Kono, Jun Takeda, Ikufumi Katayama

Format: Article
Diterbitkan: Nature Portfolio 2022-07-01

Deskripsi

Valley depolarization processes in 2D transition metal dichalcogenides have been linked to acoustic phonons, but optical verification is ambiguous, due to the nearly degenerate acoustic phonon frequencies at the zone-edge. Here, the authors determine the phonon momentum of the longitudinal acoustic (LA) phonons at the K point as responsible for the ultrafast valley depolarization in monolayer MoSe2.