  We describe a mechanism by which both ferroelectric polarization and
magnetization can be created in nonpolar, nonmagnetic materials. Using a
combination of phenomenological modeling and first-principles calculations, we
demonstrate that ferroelectric polarization, magnetization, or both
simultaneously can be transiently induced by an ultrashort laser pulse upon
linearly, circularly, or elliptically polarized excitation of phonon modes in
$\gamma$-LiBO$_2$. The direction and magnitude of the multiferroic polarization
can be controlled by the chirality of the laser pulse and the phonon modes,
offering a pathway for controlling multiferroicity and magnetoelectricity on
ultrafast timescales.
