  Optical torque on individual atoms in a Bose-Einstein condensate can rotate
the ensemble and generate a current flow [Phys. Rev. A 82, 051402 (2010)]. We
exploit the fact to suggest a new mechanism for enhanced and well-controlled
rotational motions and show how atoms, interacting with Laguerre-Gaussian
beams, experience a torque whose features depend on relative phase of applied
fields so that zero and large positive, or even negative, values for the torque
can be obtained. Such controllable torque, along with simplicity of tuning the
relative phase, can simplify a possible implementation of current flows in
Bose-Einstein condensates.
