  We present a microscopic theory for transport of the spin polarized charge
density wave with both electrons and holes in the $(111)$ GaAs quantum wells.
We analytically show that, contradicting to the commonly accepted belief, the
spin and charge motions are bound together only in the fully polarized system
but can be separated in the case of low spin polarization or short spin
lifetime even when the spatial profiles of spin density wave and charge density
wave overlap with each other. We further show that, the Coulomb drag between
electrons and holes can markedly enhance the hole spin diffusion if the hole
spin motion can be separated from the charge motion. In the high spin polarized
system, the Coulomb drag can boost the hole spin diffusion coefficient by more
than one order of magnitude.
