  In this paper, we discuss quantum friction in a system formed by two metallic
surfaces separated by a ferromagnetic intermedium of a certain thickness. The
internal degrees of freedom in the two metallic surfaces are assumed to be
plasmons, while the excitations in the intermediate material are magnons,
modeling plasmons coupled to magnons. During relative sliding, one surface
moves uniformly parallel to the other, causing friction in the system. By
calculating the effective action of the magnons, we can determine the particle
production probability, which shows a positive correlation between the
probability and the sliding speed. Finally, we derive the frictional force of
the system, with both theoretical and numerical results indicating that the
friction, like the particle production probability, also has a positive
correlation with the speed.
