  We introduce a new scheme for controlling the sense of molecular rotation. By
varying the polarization and the delay between two ultrashort laser pulses, we
induce unidirectional molecular rotation, thereby forcing the molecules to
rotate clockwise/counterclockwise under field-free conditions. We show that
unidirectionally rotating molecules are confined to the plane defined by the
two polarization vectors of the pulses, which leads to a permanent anisotropy
in the molecular angular distribution. The latter may be useful for controlling
collisional cross-sections and optical and kinetic processes in molecular
gases. We discuss the application of this control scheme to individual
components within a molecular mixture in a selective manner.

Quantum Physics