Full control of the spin-wave damping in a magnetic insulator using spin-orbit torque

• Published in: Physical review letters Vol. 113; no. 19; p. 197203
• Main Authors: Hamadeh, A, d'Allivy Kelly, O, Hahn, C, Meley, H, Bernard, R, Molpeceres, A H, Naletov, V V, Viret, M, Anane, A, Cros, V, Demokritov, S O, Prieto, J L, Muñoz, M, de Loubens, G, Klein, O
• Format: Journal Article
• Language: English
• Published: United States American Physical Society 07-11-2014
• Subjects: Compensation; Damping; Insulators; Magnetization; Microscopes; Physics; Polarity; Threshold currents; Torque
• ISSN: 0031-9007; 1079-7114
• DOI: 10.1103/physrevlett.113.197203

It is demonstrated that the threshold current for damping compensation can be reached in a 5  μm diameter YIG(20  nm)|Pt(7  nm) disk. The demonstration rests upon the measurement of the ferromagnetic resonance linewidth as a function of I(dc) using a magnetic resonance force microscope (MRFM). It is shown that the magnetic losses of spin-wave modes existing in the magnetic insulator can be reduced or enhanced by at least a factor of 5 depending on the polarity and intensity of an in-plane dc current I(dc) flowing through the adjacent normal metal with strong spin-orbit interaction. Complete compensation of the damping of the fundamental mode by spin-orbit torque is reached for a current density of ∼3×10(11)  A·m(-2), 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.