The spin and valley degrees of freedom in two-dimensional (2D) materials provide new opportunities for information storage, non-volatile logic, and optoelectronics. Among all materials, graphene exhibits the best properties for spin transport, exhibiting long spin lifetime (13 ns) and spin diffusion length (>30 µm) at room temperature. Combining graphene with other 2D materials presents unique opportunities in the form of hybrid 2D systems with new functionalities.
In this talk, I’ll first briefly review graphene spintronics and the ‘hallmark’ Hanle spin precession measurement in non-local spin valves. Then I’ll present our recent developments in hybrid 2D optospintronic systems, where we achieved the first demonstration of opto-valleytronic spin injection across transition-metal dichalcogenide(TMD)/graphene interface. Our results demonstrate a hybrid 2D spintronic/valleytronic system that exhibits optical spin injection and lateral spin transport at room temperature in a single device. Additionally, I will discuss our ongoing work investigating the strong and complex electrical and photonic tunability of photon-charge conversion in dual-gated field-effect van der Waals heterostructures, as well as our progress in integrating 2D magnets with graphene for high-efficiency spin injection and spin transport.