Spin-valley coupling and spin-relaxation anisotropy in all-CVD Graphene- MoS2 van der Waals heterostructure

Abstract

Two-dimensional (2D) van der Waals (vdW) heterostructures fabricated by combining 2D materials with unique properties into one ultimate unit can offer a plethora of fundamental phenomena and practical applications. Recently, proximity-induced quantum and spintronic effects have been realized in heterostructures of graphene (Gr) with 2D semiconductors and their twisted systems. However, these studies are so far limited to exfoliated flake-based devices, limiting their potential for scalable practical applications. Here, we report spin-valley coupling and spin-relaxation anisotropy in Gr-MoS2 heterostructure devices prepared from scalable chemical vapor-deposited (CVD) 2D materials. Spin precession and dynamics measurements reveal an enhanced spin-orbit coupling strength in the Gr-MoS2 heterostructure in comparison with pristine Gr at room temperature. Consequently, large spin-relaxation anisotropy is observed in the heterostructure, providing a method for spin filtering due to spin-valley coupling. These findings open a scalable platform for all-CVD 2D vdW heterostructures design and their device applications.