  Helical metals realized at the surfaces of topological insulators have
recently attracted wide attention due to their potential applications in
spintronics. In this paper we propose to realize helical metals through the
application of THz light on common two-dimensional semiconductors and discuss
their observable properties. We show that the application of circularly
polarized light enables coherent manipulation of magnetization. Moreover, for a
range of chemical potentials the system behaves as a helical metal, exhibiting
a large anomalous Hall conductivity and associated magnetoelectric effect.
Proposed dynamical engineering of material properties through light in
much-studied materials opens new perspectives for future applications.
