We utilize micro-focus Brillouin light scattering spectroscopy to study the interaction of spin current generated by the spin Hall effect with magnetic fluctuations in a Permalloy microdisc. We show that the fluctuations can be efficiently enhanced or suppressed by different directions of the current. Additionally, we find that the effect of spin current on magnetic fluctuations is strongly influenced by nonlinear magnon-magnon interactions. The observed phenomena can be utilized for controllable reduction of thermal noise in spintronic nanodevices.
Citation: Physical Review Letters
Pub Type: Journals
spin-transfer torque, magnetization dynamics, magnetic damping, ferromagnetic resonance, spin current, spin Hall effect, Brillouin light scattering, spin waves