Anisotropic Absorption of Pure Spin Currents

作者：Baker A A; Figueroa A I; Love C J; Cavill S A; Hesjedal T; van der Laan G

来源：Physical Review Letters, 2016, 116(4): 047201.

DOI：10.1103/PhysRevLett.116.047201

Spin transfer in magnetic multilayers offers the possibility of ultrafast, low-power device operation. We report a study of spin pumping in spin valves, demonstrating that a strong anisotropy of spin pumping from the source layer can be induced by an angular dependence of the total Gilbert damping parameter, a, in the spin sink layer. Using lab-and synchrotron-based ferromagnetic resonance, we show that an in-plane variation of damping in a crystalline Co50Fe50 layer leads to an anisotropic a in a polycrystalline Ni81Fe19 layer. This anisotropy is suppressed above the spin diffusion length in Cr, which is found to be 8 nm, and is independent of static exchange coupling in the spin valve. These results offer a valuable insight into the transmission and absorption of spin currents, and a mechanism by which enhanced spin torques and angular control may be realized for next-generation spintronic devices.

• 出版日期2016-1-27