  We demonstrate theoretically that an off-resonant circularly polarized
electromagnetic field can induce a persistent current in carbon nanotubes,
which corresponds to electron rotation about the nanotube axis. As a
consequence, the nanotubes acquire magnetic moment along the axis, which
depends on their crystal structure and can be detected in state-of-the-art
measurements. This effect and related phenomena are analyzed within the
developed Floquet theory describing the electronic properties of the nanotubes
irradiated by the field.
