Spin and Valley Hall Effect in Monolayer WSe₂ Transistors at Near-Room Temperature

Monolayer transition metal dichalcogenide (TMDC) crystals have exciting potential for spintronic applications due to their distinct spin and valley properties. Due to their inversion asymmetry and the strong spin orbit coupling, they are predicted to exhibit a coupled spin and valley Hall effect (SVHE) [1,2,3]. We investigate p-type monolayer WSe₂ transistors. We observe distinct spin-valley polarization along the two sides of the FET channel at a temperature of 240 K which a spatial distribution that indicates long spin diffusion length. Our study complements earlier reports of the Valley Hall Effect (VHE) in gated bilayer MoS₂ at 30 K [3] by showing that the SVHE can be observed near room temperature. For use in practical electronic applications, it is necessary to control the SVHE and push it towards room temperature. Our results demonstrate the robustness of the SVHE effect and the potential for spin and valley device applications.


References:
[1] K. F. Mak, K. L. McGill, J. Park, P. L. McEuen. Science 344, 1489-92 (2014).
[2] D. Xiao, G. B. Liu, W. Feng, X. Xu, W. Yao. Physical Review Letters 108, 196802 (2012).
[3] J. Lee, K. F. Mak, J. Shan. Nature Nanotechnology 11, 421-5 (2016).