Hanle effect driven by weak-localization

The influence of weak localization on Hanle effect in a two-dimensional system with spin-split spectrum is considered. We show that weak localization drastically changes the dependence of stationary spin polarization $\mathbf S$ on external magnetic field $B.$ In particular, the non-analytic dependence of $\mathbf S$ on $\mathbf B$ is predicted for III-V-based quantum wells grown in [110] direction and for [100]-grown quantum wells having equal strengths of Dresselhaus and Bychkov-Rashba spin-orbit coupling. It is shown that in weakly localized regime the components of $\mathbf S$ are discontinuous at $B=0.$ At low $B,$ the magnetic field-induced rotation of the stationary polarization is determined by quantum interference effects. This implies that the Hanle effect in such systems is totally driven by weak localization.