Classification of the equilibrium states of magnets with vector and quadrupole order parameters

Abstract

A classification of the equilibrium states of magnetic condensed media whose symmetry is broken spontaneously relative to rotations in spin space and translations in configuration space is constructed. The cases of vector and tensor order parameters, which possess different transforma-tion properties under time reversal, are examined. The conditions for unbroken symmetry and spatial symmetry of the equilibrium states for such media are formulated. In the case of a vector order parameter, the connection between these symmetry conditions and para-, ferro-, antiferro-, ferri-, and spiral magnetic states is determined. The relation of the indicated symmetry conditions with quadrupole magnetic states is determined-one-and two-axis magnetic non magnetics, mag-netic cholesterics, and a double magnetic spiral