Parametric pumping modulated by two orthogonal external magnetic fields

Modulated by two orthogonal external magnetic fields along the momentum-spin planes in a semiconductor, the parametric pumping was investigated in this work. The pumping comes from the driving of double time-dependent delta potentials, which is formed in interfaces between a semiconductor and two normal leads. Calculations by the Floquet theory show that spin and charge currents pumped from the system can be greatly modulated by the magnetic fields besides the potentials and spin-orbit couplings (SOCs). In some settled potentials and Rashba SOCs, even fine controls of the pure spin currents pumping can be achieved in some couplings of the two external magnetic fields.