Control of propagating spin-wave attenuation by the spin-Hall effect

Abstract

The spin-Hall effect induced modification of the attenuation of propagating exchange-mode spin waves (SWs) is studied micromagnetically and analytically in heavy-metal/ferromagnet bilayers. Micromagnetic simulations of spin-wave propagation in Pt/NiFe show that at a relatively low current density of ∼ 6 × 10¹¹A/m², Gilbert damping is exactly balanced by the spin-Hall torque and long-distance SW transmission is possible. An analytical model is developed to explain the micromagnetic results and relate the current density to the characteristic attenuation length. The results suggest that the spin Hall effect can be used as an effective means to control the attenuation length of propagating spin waves in nanostructures.