Construction of theory of a binary mixture of nonideal bose gases (or liquids) by the method of collective variables. II. The s-particle density matrices at T=0. Variational calculation of the ground-state energy and density-density correlation functions

Abstract

The s-particle density matrices at T = O are found by the method of collective variables for a binary mixture of nonideal Bose gases (or liquids). The variational method is used to find the ground-state energy, the excitation spectrum, and the density-density correlation functions. It is shown that the zeroth approximations of the variational and microscopic approaches are consistent. The existence of a Bose condensate in the system is established. A binary mixture of Bose gases with equal masses of the particles is considered as an illustration in the framework of the hard-sphere pseudopotential model.