Figure 1. Schematics of the Elliott-Yafet and the D'yakonov-Perel' mechanisms: 
in the EY scenario and spin-scattering occurs rarely (typically for every 104..106th momentum scattering in alkali metals), whereas the spin direction continuously precesses around the internal magnetic field due to SOC in the DP scenario, resulting in 
.
It is the topic of the present paper, how these two distinct regimes are related to each other.