Goldstone-Mode Relaxation in a Quantized Hall Ferromagnet in the Presence of Smooth Random Potential

We discuss the spin relaxation of a strongly correlated two-dimensional (2D) electron gas (2DEG) in the quantized Hall regime when the filling factor is close to an odd-integer. As the initial state we consider a coherent deviation of the spin system from the ${\bf B}$ direction and investigate a break-down of this Goldstone-mode state due to the spin-orbit (SO) coupling and smooth disorder. The spin relaxation (SR) process is considered in terms of annihilation transitions in the system of spin excitons (magnons).