THEORY OF SUPERFLUID FERMI-LIQUID

This review develops the Fermi liquid approach to the theory of superfluidity based on the generalization of the combinatorial expression for the entropy for the case when the state of the Fermi liquid is described not only by a normal distribution function but by an abnormal distribution one. The energy of the superfluid Fermi liquid is specified in the form of a functional of these functions. The Fermi liquid approach is equivalent to the BCS theory in the weak interaction approximation. The interaction of the Fermi liquid with electromagnetic field is included in a gauge-invariant way. The theory of a triplet pairing is developed as well as the theory of a singlet pairing. On the base of the united variational principle leading to the theory of superfluidity (superconductivity) London's equations and Ginzburg-Landau's equation are obtained. Applications of the theory connected with the construction of ideal two-component hydrodynamic equations are considered. 2 figs. 44 refs. (47 titls.).