Teams from the University of York and Roma Tre University state that ultra-low-power transistors could be built using composite materials based on single layers of graphene and transition metal dichalcogenides (TMDC). These materials, they note, could be used to achieve a sought-after electrical control over electron spin.
The teams explained “we found this can be achieved with little effort when 2D graphene is paired with certain semiconducting layered materials. Our calculations show that the application of small voltages across the graphene layer induces a net polarization of conduction spins". The team showed that when a small current is passed through the graphene layer, the electrons’ spin polarize in plane due to ‘spin-orbital’ forces brought about by the proximity to the TMDC base. They also showed the efficiency of charge-to-spin conversion can be quite high, even at room temperature.
The researchers believe this work will attract ‘substantial interest’ from the spintronics community. “The flexible, atomically thin nature of the graphene-based structure is a major advantage for applications. Also, the presence of a semiconducting component opens up the possibility for integration with optical communication networks.”