Reduction of momentum and spin relaxation rate in strained thin silicon films

We investigate the surface roughness and phonon induced spin and momentum relaxation in ultra-scaled SOI MOSFETs. We show that the spin-flip hot spots characterized by strong spin relaxation can be efficiently removed by applying shear strain resulting in an increase of spin lifetime by orders of magnitude. In contrast, the momentum relaxation time in ultrathin films, which is mostly determined by surface roughness scattering can be only increased by a factor of two, in agreement with strain-induced mobility enhancement data.