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Soviet Journal of Low Temperature Physics

Collective excitations in a superfluid Fermi liquid

Красильников Владимир Владимирович, A. A. Rozhkov, A. A. Yatsenko

Published Nov 1, 1990• 1 citation
Publisher

Abstract

The superfluid and normal states of a Fermi liquid are described by using a semiphenomenological theory. The collective excitation spectrum in the superfluid Fermi liquid is investigated on the basis of linearized kinetic equations for the normal and anomalous distribution functions.
DOI
10.1063/10.0032725

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The Fermi-liquid approach generalized to superfluid systems is used to derive general formulas for the normal and abnormal distribution functions (DF) for quasiparticles of a superfluid Fermi liquid (SFL) consisting of electrically neutral fermions with spin-triplet pairing (the spin of a pair s=1, the orbital angular momentum l of the pair being an arbitrary odd number) in a static uniform magnetic field, taking into account the Landau spin-exchange Fermi-liquid interaction at temperatures 0<T<Tc (Tc is the temperature of phase transition from the normal to the superfluid state). In deriving the DF, the explicit form of the energy functional (EF) for SFL is not used. A system of coupled equations is obtained for the order parameter, energy of quasiparticles, and effective magnetic field for the SFL under investigation in the case of an EF quadratic in DF. The obtained DF and the system of equations are applicable for describing both unitary and nonunitary phases of superfluid He3 in a magnetic field, e.g., for determining the magnetization and magnetic susceptibility of these phases.