  Matos, Guzman and Nunez proposed a model of galactic halo based on an
exponential-potential scalar field that could induce a rotation curve that is
constant for all radii. We demonstrate that with suitable boundary conditions,
such scalar field dark matter (SDM) can not only produce the observed constant
rotation curve at large radius but also give rise to the correct power-law
scaling near the galactic core region. This solves the existing cusp-core
problem faced by the conventional cold dark matter (CDM) model.
