Control of atomic rotation by elliptical hollow beam carrying zero angular momentum

The interaction between linearly polarized elliptical hollow beam and a two-level atom is investigated theoretically. Although the linearly polarized elliptical hollow beam does not carry angular momentum, it can produce very high torque. The atoms initially at rest and located at off-beam-axis positions will rotate under the drive of the torque of the beam. The shorter the distance from the original location of atom to the axis is, the larger the average angular frequency of atom rotation is. The average angular frequency can reach as high as 1000 Hz. This convinces us that the elliptical hollow beam might be a useful tool in the study of quantum property of Bose–Einstein condensate or ultra cold atom media.