Spin Hall Effect in Bilayer Graphene Combined with an Insulator up to Room Temperature
C. K. Safeer, Josep Ingla‐Aynés, Nerea Ontoso, Franz Herling, Wenjing Yan, Luis E. Hueso, Fèlix Casanova
Abstract
Spin-orbit coupling in graphene can be enhanced by chemical functionalization, adatom decoration, or proximity with a van der Waals material. As it is expected that such enhancement gives rise to a sizable spin Hall effect, a spin-to-charge current conversion phenomenon of technological relevance, it has sparked wide research interest. However, it has only been measured in graphene/transition-metal dichalcogenide van der Waals heterostructures with limited scalability. Here, we experimentally demonstrate the spin Hall effect up to room temperature in graphene combined with a nonmagnetic insulator, an evaporated bismuth oxide layer. The measured spin Hall effect arises most likely from an extrinsic mechanism. With a large spin-to-charge conversion efficiency, scalability, and ease of integration to electronic devices, we show a promising material heterostructure suitable for spin-based device applications.