  We consider the magnetic response of a two-dimensional electron gas (2DEG)
with a spin-orbit interaction to a long-wave-length electromagnetic excitation.
We observe that the transverse electric field creates spin polarization
perpendicular to the 2DEG plane. The effect is more prominent in clean systems
with resolved spin-orbit-split subbands, and reaches maximum when the frequency
of the wave matches the subband splitting at the Fermi momentum. The relation
of this effect to the spin-Hall effect is discussed.
