  We use the Bogoliubov-de Gennes formalism to analyze the ground state phases
of harmonically trapped two-species fermion mixtures with unequal masses. In
the weakly attracting limit and around unitarity, we find that the superfluid
order parameter is spatially modulated around the trap center, and that its
global maximum occurs at a finite distance away from the trap center where the
mixture is locally unpolarized. As the attraction strength increases towards
the molecular limit, the spatial modulations gradually disappear while the
Bardeen-Cooper-Schrieffer (BCS) type nonmodulated superfluid region expands
until the entire mixture becomes locally unpolarized.
