  A spin-rotation mode emerging in a quantum Hall ferromagnet due to laser
pulse excitation is studied. This state, macroscopically representing a
rotation of the entire electron spin-system to a certain angle, is not
microscopically equivalent to a coherent turn of all spins as a single-whole
and is presented in the form of a combination of eigen quantum states
corresponding to all possible S_z spin numbers. The motion of the macroscopic
quantum state is studied microscopically by solving a non-stationary
Schroedinger equation and by means of a kinetic approach where damping of the
spin-rotation mode is related to an elementary process, namely, transformation
of a `Goldstone spin exciton' to a `spin-wave exciton'. The system exhibits a
spin stochastizationa mechanism (determined by spatial fluctuations of the
Land'e g-factor) ensuring damping, transverse spin relaxation, but irrelevant
to decay of spin-wave excitons and thus not involving longitudinal relaxation,
i.e., recovery of the S_z number to its equilibrium value.
