  We demonstrate excitation of the gyrotropic mode in a magnetostrictive vortex
by time-varying strain. The vortex dynamics is driven by a time-varying voltage
applied to the piezoelectric substrate and detected electrically by spin
rectification at subthreshold values of rf current. When the frequency of the
time-varying strain matches the gyrotropic frequency at given in-plane magnetic
field, the strain-induced in-plane magnetic anisotropy leads to a resonant
excitation of the gyration dynamics in a magnetic vortex. We show that
nonlinear gyrotropic dynamics can be excited already for moderate amplitudes of
the time-varying strain.
