  Recently, it was predicted theoretically and verified experimentally that a
pair of delayed and cross-polarized short laser pulses can create molecular
ensembles with a well defined sense of rotation (clockwise or
counterclockwise). Here we provide a comparative study of the classical and
quantum aspects of the underlying mechanism for linear molecules and for
symmetric tops, like benzene molecules, that were used for the first
experimental demonstration of the effect. Very good quantitative agreement is
found between the classical description of the process and the rigorous quantum
mechanical analysis at the relevant experimental conditions. Both approaches
predict the same optimal values for the delay between pulses and the angle
between them, and deliver the same magnitude of the induced oriented angular
momentum of the molecular ensemble. As expected, quantum and classical analysis
substantially deviate when the delay between pulses is comparable with the
period of quantum rotational revivals. However, time-averaged characteristics
of the excited molecular ensemble are equally good described by the these two
approaches. This is illustrated by calculating the anisotropic time-averaged
angular distribution of the double-pulse excited molecules, which reflects
persistent confinement of the molecular axes to the rotation plane defined by
two polarization vectors of the pulses.
