GRISOTO · GRaphene-Interfaced heterostructures for Spin Orbit TOrques

Materials that exhibit two-dimensional transport are in the spotlight in the search for scalable systems and novel functionalities. By combining graphene, which possesses very large electronic mobility, with materials with large spin-orbit coupling, one expects to benefit from both of these properties for future practical applications in spintronics. In fact, the use of large spin-orbit coupling for conversion from charge to spin current, as well as the manipulation of the magnetization of ferromagnetic layers using spin-orbit torques (SOT), are the most promising mechanisms for the next generation of magnetic memories. Proximity spin-orbit coupling in graphene has been recently demonstrated by the host group. However, it is still poorly understood, it requires optimization and its envisioned applications are still to be explored. In the present project, we propose to investigate the proximity effect between graphene and materials exhibiting 2D transport and large spin-orbit coupling (2D-SOM) such as topological insulators (TIs) and transition metal dichalcogenides (TMDs), with a particular focus on the generation of large SOT.Our research program involves fabrication of 2D-SOM/graphene/ferromagnet heterostructures, including the growth of TIs using state-of-the art molecular beam epitaxy, device design, nanofabrication and characterization. The magnetization dynamics and the charge-to-spin conversion efficiency will be studied in these heterostructures using spin-torque ferromagnetic resonance. We will seek heterostructures that display large SOT. Their optimization will allow us to demonstrate full electrical magnetization reversal of a magnetic element via SOT. If successful, the outcomes of this work will advance the understanding of the proximity effect of graphene with 2D-SOM, as well as its influence on SOT, and will contribute to the unlocking of next-generation devices such as memories based on the exploitation of spin-orbit coupling.