2014

Magnon-Mediated Dzyaloshinskii-Moriya Torque in Homogeneous Ferromagnets

Magnon-Mediated Dzyaloshinskii-Moriya Torque in Homogeneous Ferromagnets
A. Manchon, P.B. Ndiaye, J.-H. Moon, H.-W. Lee, and K.-J. Lee
Phys. Rev. B 90, 224403 (2014)​​
A. Manchon, P.B. Ndiaye, J.-H. Moon, H.-W. Lee, K.-J. Lee
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2014
​In thin magnetic layers with structural inversion asymmetry and spin-orbit coupling, the DzyaloshinskiiMoriya interaction arises at the interface. When a spin-wave current jm flows in a system with a homogeneous magnetization m, this interaction produces an effective fieldlike torque of the form TFL ∝ m × (z × jm) as well as a dampinglike torque, TDL ∝ m × [(z × jm) × m], the latter only in the presence of spin-wave relaxation (z is normal to the interface). These torques mediated by the magnon flow can reorient the time-averaged magnetization direction and display a number of similarities with the torques arising from the electron flow in a magnetic two-dimensional electron gas with Rashba spin-orbit coupling. This magnon-mediated spin-orbit torque can be efficient in the case of magnons driven by a thermal gradient.