Nontrivial dynamics of spins under the action of mutually perpendicular constant and variable magnetic fields

The paper considers the nontrivial dynamics of a spin when it is simultaneously affected by a constant magnetic field directed along the Z axis and a variable one applied to the XOY plane. It is shown that coupled oscillations of all components of the magnetic moment (or magnetization) arise in this case. In other words, it becomes possible to control the orientation of the magnetic moment. Further, it was found that this possibility remains even in the case of two constant magnetic fields – when they are perpendicular to each other. In the latter case, elliptical precessions of magnetic moments occur in planes perpendicular to the applied fields, the amplitudes of which can be changed by means of constant magnetic fields.