Electrical Control of Valley-Zeeman Spin-Orbit-Coupling-Induced Spin Precession at Room Temperature

The ultimate goal of spintronics is achieving electrically controlled coherent manipulation of the electron spin at room temperature to enable devices such as spin field-effect transistors. With conventional materials, coherent spin precession has been observed in the ballistic regime and at low temperatures only. However, the strong spin anisotropy and the valley character of the electronic states in 2D materials provide unique control knobs to manipulate spin precession. Here, by manipulating the anisotropic spin-orbit coupling in bilayer graphene by the proximity effect to WSe2, we achieve coherent spin precession in the absence of an external magnetic field, even in the diffusive regime. Remarkably, the sign of the precessing spin polarization can be tuned by a back gate voltage and by a drift current. Our realization of a spin field-effect transistor at room temperature is a cornerstone for the implementation of energy efficient spin-based logic.

Automated summary

The ultimate goal of spintronics is to achieve electrically controlled coherent manipulation of electron spin at room temperature for devices such as spin field-effect transistors. The use of 2D materials with strong spin anisotropy and valley character provides unique control knobs for manipulating spin precession. Experimental results have shown successful coherent spin precession in the absence of an external magnetic field, even in the diffusive regime, by manipulating spin-orbit coupling in bilayer graphene.