Propagation of solitary waves in a mixture of liquid3He and superfluid4He

The effect of an admixture of liquid3He on the propagation of solitary waves in superfluid4He 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 the3He impurity.