Symmetry and the macroscopic dynamics of magnetic materials
A.F. Andreev a
a Kapitza Institute of Physical Problems, Russian Academy of Sciences, ul. Kosygina 2, Moscow, 117334, Russian Federation
A systematic exposition is given of a recently developed theory of the low-frequency spin dynamics of any magnetic material in which the magnetic order is caused by exchange forces that considerably exceed the relativistic interactions. The proposed approach does not use any model representations of the state of the magnet (localized spins, sublattices, etc.). A fundamental concept in the theory is that of approximate exchange symmetry.