Anatolii P. IVASHIN, Mikhail Y. KOVALEVSKY
National Science Center "Kharkov Institute of Physics & Technology",
1 Akademicheskaya Str.,
61108 Kharkov, UKRAINE

Belgorod State University,
Belgorod, RUSSIA

Classification of equilibrium states of condensed media with spontaneously broken symmetry

In the present paper the classification of equilibrium states of condensed media with spontaneously broken symmetry is carried out in view of possible nonuniform structure. The used approach is founded on the quasiaverages concept [1, 2]. The admissible properties of equilibrium state symmetry of a quantum fluid and relevant structures of an order parameter are found from requirements of the residual and spatial symmetry at nonzero values of an order parameter. This approach is founded on the representation of the residual symmetry of the degenerated equilibrium state as a subgroup of a normal phase symmetry. The superfluid liquid in a state with singlet and triplet pairing [3, 4], the superfluid nuclear matter in a state of d-pairing [5], liquid crystal states of matter are consedered in this paper as the axamples. Admissible conditions of the spatial symmetry and the general structure of the corresponding generator are found. The requirement of residual symmetry is expanded on the inhomogeneous equilibrium states, the relation to the homogeneous case has been found.


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