  Spin relaxation dynamics in rings with Rashba spin-orbit coupling is
investigated using spin kinetic equation. We find that the spin relaxation in
rings occurs toward a persistent spin configuration whose final shape depends
on the initial spin polarization profile. As an example, it is shown that a
homogeneous parallel to the ring axis spin polarization transforms into a
persistent crown-like spin structure. It is demonstrated that the ring geometry
introduces a geometrical contribution to the spin relaxation rate speeding up
the transient dynamics. Moreover, we identify several persistent spin
configurations as well as calculate the Green function of spin kinetic
equation.
