Ultrafast non-excitonic valley Hall effect in MoS2/WTe2 heterobilayers
SCIE
SCOPUS
- Title
- Ultrafast non-excitonic valley Hall effect in MoS2/WTe2 heterobilayers
- Authors
- Lee, Jekwan; Heo, Wonhyeok; Cha, Myungjun; Watanabe, Kenji; Taniguchi, Takashi; Kim, Jehyun; Cha, Soonyoung; Kim, Dohun; Jo, Moon-Ho; Choi, Hyunyong
- Date Issued
- 2021-03
- Publisher
- Nature Publishing Group
- Abstract
- AbstractThe valley Hall effect (VHE) in two-dimensional (2D) van der Waals (vdW) crystals is a promising approach to study the valley pseudospin. Most experiments so far have used bound electron-hole pairs (excitons) through local photoexcitation. However, the valley depolarization of such excitons is fast, so that several challenges remain to be resolved. We address this issue by exploiting a unipolar VHE using a heterobilayer made of monolayer MoS2/WTe2 to exhibit a long valley-polarized lifetime due to the absence of electron-hole exchange interaction. The unipolar VHE is manifested by reduced photoluminescence at the MoS2 A exciton energy. Furthermore, we provide quantitative information on the time-dependent valley Hall dynamics by performing the spatially-resolved ultrafast Kerr-rotation microscopy; we find that the valley-polarized electrons persist for more than 4 nanoseconds and the valley Hall mobility exceeds 4.49 × 103 cm2/Vs, which is orders of magnitude larger than previous reports.
- URI
- https://oasis.postech.ac.kr/handle/2014.oak/109565
- DOI
- 10.1038/s41467-021-21013-w
- ISSN
- 2041-1723
- Article Type
- Article
- Citation
- Nature Communications, vol. 12, no. 1, 2021-03
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- There are no files associated with this item.
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