Electric-field-induced ferromagnetic resonance excitation in an ultrathin ferromagnetic metal layer

Using resonant phenomena to exert coherent control over electron spin dynamics could enable more-energy-efficient spintronic devices and related technologies. Yet, achieving collective spin resonant control by ferromagnetic resonance excitation most often requires radiofrequency magnetic fields or the injection of spin-polarized currents that consume relatively large amounts of power. Inducing ferromagnetic resonances directly with an electric field offers a lower-power alternative to these, but doing so requires strong electric and magnetic coupling that is difficult to realize owing to screening effects, particularly in metallic materials. Here, we demonstrate electric-field-induced ferromagnetic resonance excitation by means of voltage control over the magnetic anisotropy in a few monolayers of FeCo at room temperature. The technique provides a low-power, highly localized and coherent means to manipulate electron spin dynamics.