  Systems of atoms or molecules can possess nonzero total spins that can be
employed in spintronics, for instance for creating memory devices, which
requires to be able to efficiently regulate spin directions. This article
presents some methods of regulating spin dynamics, developed by the authors.
These methods can be applied for different physical systems, described by
different Hamiltonians including the interactions of spins with magnetic
fields. The principal feature of the methods is the use of the feedback fields
formed by moving spins.
