Nonadiabatic pure spin pumping in zigzag graphene nanoribbons with proximity induced ferromagnetism

• Charge and spin pumping in ferromagnetic driven graphene nanoribbons.
• Pure spin current by tuning driving frequency in non-adiabatic regime.
• A crossover from adiabatic to non-adiabatic pumping.

By combining Floquet theory with Green's function formalism, we present non-adiabatic quantum spin and charge pumping through a zigzag ferromagnetic graphene nanoribbon including a double-barriers structure driven weakly by two local ac gate voltages operating with a phase-lag. Over a wide range of Fermi energies, interesting quantum pumping such as (i) pure spin pumping with zero net charge pumping, (ii) pure charge pumping and (iii) fully spin polarized pumping can be achieved by tuning and manipulating driving frequency in the non-adiabatic regime. Spin polarized pumping which is measurable using the current technology depends on the competition between the energy level spacing and the driving frequency.