  Comment on S.-Q. Shen, Phys. Rev. Lett. 95, 187203 (2005) [cond-mat/0506676].
We show that the equations of motion deduced by Shen are incorrect and derive
semiclassical expression for the operator of force, which also contains a term
of the transverse spin force but twice as large in magnitude.

Mesoscale and Nanoscale Physics;Other Condensed Matter