Friction by spin waves

Spin waves cause non-linear friction.
M. P. Magiera, L. Brendel, D. E. Wolf and U. Nowak
Eur. Phys. Lett. 91, 17010 (2011)

(a) Friction force for several velocities, with the non-confined part marked by the shading. (b) Nonconfined
contributions to the friction force times velocity as well as the function B(v −v0)4, where v0 has been taken from
eq. (16).