Small Angle Shubnikov-de Haas Measurements in Silicon MOSFET's: the   Effect of Strong In-Plane Magnetic Field
  Measurements in magnetic fields applied at small angles relative to the electron plane in silicon MOSFETs indicate a factor of two increase of the frequency of Shubnikov-de Haas oscillations at H>H_{sat}. This signals the onset of full spin polarization above H_{sat}, the parallel field above which the resistivity saturates to a constant value. For H<H_{sat}, the phase of the second harmonic of the oscillations relative to the first is consistent with scattering events that depend on the overlap instead of the sum of the spin-up and spin-down densities of states. 
Sergey A. Vitkalov, Hairong Zheng, K. M. Mertes, M. P. Sarachik, and   T. M. Klapwijk