  We investigate theoretically the dynamic multiferroic response of coupled
ferroelectric/ferromagnetic composites upon excitation by a photo-induced
acoustic strain pulse. Two magnetoelectric mechanisms are considered: interface
strain- and charge-mediated magnetoelectric couplings. The former results in
demagnetization, depolarization and repolarization within tens of picoseconds
via respectively magnetostriction and piezoelectricity. Charge magnetoelectric
interaction affects the ferroelectric/ferromagnetic feedback response leading
to magnetization recovery. Experimental realization based on time-resolved
x-ray diffraction is suggested. The findings indicate the potential of
composite multiferroics for photo-steered, high-speed, multi-state electronic
devices.
