  Using the perturbative method for the simulation of charmed particles, the
dynamical origin of charm quark elliptic flow is studied in the framework of a
multi-phase transport (AMPT) model. Besides the expected ordering relative to
that of light quarks according to quark masses, charm quark elliptic flow is
seen to be sensitive to the parton scattering cross section. To describe the
observed large elliptic flow of electrons from the decay of charmed mesons, a
charm quark elastic scattering cross section much larger than that estimated
from the perturbative QCD is required.
