Another approach for obtaining the excitation spectra in degenerate Bose gases with delta-shaped interaction potentials

Abstract

A formalism is proposed for describing an equilibrium Bose gas based on consideration of a macroscopic but finite volume. The presence of a Bose-Einstein condensate is taken into account through an off-diagonal long-range order in the transition to the thermodynamic limit. On this basis, degenerate Bose gases with delta-shaped interaction potentials are described in terms of a self-consistent Hartree-Fock approximation. Explicit expressions are obtained for the energy spectra of single-particle and collective excitations.

Aspects of Bose-Einstein condensation in a charged boson system over the dielectric surface

“…Below, we solve Eq. ( 36) numerically by supplementing it with the minimization procedure for the energy functional governed by the Hamiltonian (31). In dimensionless variables, this functional can be written as…”

“…Among the succeeding theoretical studies, Refs. [28][29][30][31] and references therein should be mentioned. These were still focused rather on dense systems, e.g., superfluids, which under certain conditions can be described as Coulomb systems [31], plasma or even cosmological systems [29,30].…”

“…[28][29][30][31] and references therein should be mentioned. These were still focused rather on dense systems, e.g., superfluids, which under certain conditions can be described as Coulomb systems [31], plasma or even cosmological systems [29,30]. A special attention was given to the effect of the BEC of charged bosons on the Debye screening in plasma (or in Coulomb systems), as well as on the propagation and polarization of photons in cosmological plasma.…”

“…In Refs. [29][30][31] and references therein, the issue of compensation is solved by introducing a background of oppositely charged particles. For this reason, a special attention is given to studies of the effect of screening of charges and the influence of a BEC consisting of positive charges on it.…”

“…In a number of studies, including Refs. [22][23][24][25][26][28][29][30][31], the existence of compensation for the Coulomb repulsion is simply postulated.…”