Characteristics of superfluid flow along a substrate with impurities
Abstract
It is shown that the normal component generated by substrate impurities represents a fluid mass associated with the impurity centers, while the normal Landau density is a mass connected to thermal fluctuations in the density of the fluid. Based on this interpretation of the normal component, a semiphenomenological method is proposed for describing superfluid flows. For a weakly nonideal Bose gas and low impurity concentration, a microscopic theory of superfluid flow along a substrate with impurities is constructed without assuming the presence of a Bose condensate in the system. The wave function of the ground state of the system, the density distribution near an impurity center, and the density-density correlation function are found. The response of the system to rotation of the substrate is calculated and the normal density, generated by impurities at T = 0, is determined.