A micromagnetic study of the influences of electric currents and magnetic fields on the Spin-Cherenkov effect

It was predicted recently that a Spin-Cherenkov effect (SCE) would occur if the magnetic medium is disturbed by a moving object with its velocity reaching the propagating speed of spin waves (SWs). By a simulation study, we show that the applications of electric currents and magnetic fields in a ferromagnetic nanowire can effectively lower the minimum SW phase velocity and thus the SCE threshold by altering the SW dispersion relation. These results should help to ease the experimental realizations of the SCE, which could open a new route for SW excitations in ferromagnetic systems.