Harvard University

Shaking ferromagnets with electric fields: instabilities, dissipation, and noise

Abstract: Spin dynamics accompanying electric currents in nonuniform ferromagnets give rise to spin torques acting on the magnetization, which can profoundly affect ferromagnetic dynamics. Large enough currents can lead to magnetic instabilities and even chaotic behavior. I will derive self-consistent equations of motion for the magnetization in the presence of electric currents and discuss their implications for domain-wall dynamics and spin-wave instabilities. The physical meaning of the results can be understood by considering spin currents in magnetic superlattices.