Cooperative Charge Pumping and Enhanced Skyrmion Mobility

International audience; It is well known that moving magnetic textures may pump spin and charge currents along the direction ofmotion, a phenomenon called electronic pumping. Here, the electronic pumping arising from the steadymotion of ferromagnetic skyrmions is investigated by solving the time evolution of the Schrödingerequation implemented on a tight-binding model with the statistical physics of the many-body problem. Incontrast with rigid one-dimensional magnetic textures, we show that steadily moving magnetic skyrmionsare able to pump large dc currents. This ability arises from their nontrivial magnetic topology, i.e., thecoexistence of the spin-motive force and the topological Hall effect. Based on an adiabatic scatteringtheory, we compute the pumped current and demonstrate that it scales with the reflection coefficient of theconduction electrons against the skyrmion. In other words, in the semiclassical limit, reducing the size ofthe skyrmion and the width of the nanowire enhances this effect, making it scalable. We propose that such aphenomenon can be exploited in the context of racetrack devices, where the electronic pumping enhancesthe collective motion of the train of skyrmions.