Creating a pure spin current in graphene

Creating a pure spin current in graphene: "“Pure spin current is a spin current with zero charge current, which means electrons with different spins travel toward opposite directions"...

“[Adiabatic pumping] is a quantum phenomenon in which a DC current is generated without a DC voltage. Two AC voltages are applied to the graphene and a DC charge current can be generated through adiabatic quantum pumping. Adiabatic means the rates of change of the voltages are very slow in comparison with the speed at which the electrons travel through the graphene structure.”"