Propagation of solitary waves in a mixture of liquid ³He and superfluid ⁴He

Abstract

The effect of an admixture of liquid ³He on the propagation of solitary waves in superfluid ⁴He is investigated. In the local density approximation, the mean field equations are reduced to the two-fluid equations describing the dynamics of the mixture of two liquids. The nonlinear perturbation approach is used to obtain a set of equations describing the density and velocity fluctuations of the homogeneous mixture at rest. The self-consistent solution of these equations is shown to be the solitary waves. Using a pseudopotential method, we perform numerical calculations to study the changes in the general properties of the waves caused by the ³He impurity.