Spin polarization dependence of the coulomb drag at large r_s

We find that the temperature dependence of the drag resistivity between two dilute two-dimensional hole systems exhibits an unusual dependence upon spin polarization. Our main observation is that near the apparent metal-insulator transition, the temperature dependence of the drag, given by T ^α, weakens significantly with the application of a parallel magnetic field (B_∥), with a saturating at half its zero field value for B_∥ > B*, where B* is the polarization field.