Service de Physique de l’État Condensé, CEA-Saclay
“Electronic control of the spin-wave damping in a magnetic insulator”
Abstract: We show that the decay time of spin-wave modes existing in a magnetic insulator can be reduced or enhanced by injecting an in-plane dc current, Idc , in an adjacent normal metal having a strong spin-orbit interaction. The demonstration rests upon the measurement of the ferromagnetic resonance linewidth as a function of Idcin a 5 μm diameter YIG(20nm)|Pt(7nm) disk using a magnetic resonance force microscope (MRFM). Complete compensation of the damping of the fundamental mode is obtained for a current density of ∼3•1011 amps/m2, in agreement with theoretical predictions. At this critical threshold the MRFM detects a small change of static magnetization, a behavior consistent with the onset of an auto-oscillation regime.