  We demonstrate that ferromagnetic and antiferromagnetic excitations can be
triggered by the dynamical spin accumulations induced by the bulk and surface
contributions of the spin Hall effect. Due to the spin-orbit interaction, a
time-dependent spin density is generated by an oscillatory electric field
applied parallel to the atomic planes of Fe/W(110) multilayers. For symmetric
trilayers of Fe/W/Fe in which the Fe layers are ferromagnetically coupled, we
demonstrate that only the collective out-of-phase precession mode is excited,
while the uniform (in-phase) mode remains silent. When they are
antiferromagnetically coupled, the oscillatory electric field sets the Fe
magnetizations into elliptical precession motions with opposite angular
velocities. The manipulation of different collective spin-wave dynamical modes
through the engineering of the multilayers and their thicknesses may be used to
develop ultrafast spintronics devices. Our work provides a general framework
that probes the realistic responses of materials in the time or frequency
domain.
