Gate tunable spatial accumulation of valley-spin in chemical vapor deposition grown 40°-twisted bilayer WS2. (1st January 2023)

• Record Type: Journal Article
• Authors: Zhao, Siwen; Shao, Gonglei; Han, Zheng Vitto; Liu, Song; Zhang, Tongyao
• Is Part Of: Journal of semiconductors. Volume 44:Number 1(2023)
• Publication Date: 2023-01-01
• Subjects: transition metal dichalcogenides -- valleytronic devices -- light–valley interactions -- valley Hall effect; Semiconductors -- Periodicals; 621.38152
• DOI: 10.1088/1674-4926/44/1/012001
• Languages: English
• ISSNs: 1674-4926

Abstract

Abstract: The emerging two-dimensional materials, particularly transition metal dichalcogenides (TMDs), are known to exhibit valley degree of freedom with long valley lifetime, which hold great promises in the implementation of valleytronic devices. Especially, light–valley interactions have attracted attentions in these systems, as the electrical generation of valley magnetization can be readily achieved — a rather different route toward magnetoelectric (ME) effect as compared to that from conventional electron spins. However, so far, the moiré patterns constructed with twisted bilayer TMDs remain largely unexplored in regard of their valley spin polarizations, even though the symmetry might be distinct from the AB stacked bilayer TMDs. Here, we study the valley Hall effect (VHE) in 40°-twisted chemical vapor deposition (CVD) grown WS2 moiré transistors, using optical Kerr rotation measurements at 20 K. We observe a clear gate tunable spatial distribution of the valley carrier imbalance induced by the VHE when a current is exerted in the system.