Electron-magnon scattering and magnon generated chiral charge and spin pumping from time-dependent-quantum-transport/classical-micromagnetics approach

In this study, we employ recently developed [M. D. Petrovic et. al., Phys. Rev. Appl. 10, 054038 2018] multiscale time-dependent-quantum-transport/classical-micromagnetics formalism (TDNEGF-LLG) to simulate how spin-polarized steady state current of electrons interacts with a magnon modelled as a classical spin wave. We investigate electronic spin and charge currents generated by the excitation of a single frequency spin wave in a one-dimensional finite size magnetic nanowire composed of classical local magnetic moments precessing around the anisotropy axis while the phase of the precession of adjacent moments varies harmonically over the wavelength of spin wave with uniform precession cone angle. We show that spin wave hosted in the middle of two metallic leads pumps chiral electronic spin and charge currents into the leads, which can be flipped by reversing the direction of magnonic spin current carried by the spin wave. When steady spin-polarized electronic charge current is injected from the left lead into the region hosting the spin wave, we observed that outgoing electronic charge and spin currents in the right lead can be reduced or enhanced, depending on the direction of magnonic spin current.