Coexistence of the "bogolons" and the one-particle spectrum of excitations with a gap in the degenerated Bose gas

V. B. Bobrov; S. A. Trigger; I. M. Yurin

doi:10.1016/j.physleta.2010.02.075

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arXiv · 0912.1698

Coexistence of the "bogolons" and the one-particle spectrum of excitations with a gap in the degenerated Bose gas

V. B. Bobrov·S. A. Trigger·I. M. Yurin

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Abstract

Properties of the weakly non-ideal Bose gas are considered without suggestion on C-number representation of the creation and annihilation operators with zero momentum. The "density-density" correlation function and the one-particle Green function of the degenerated Bose gas are calculated on the basis of the self-consistent Hartree-Fock approximation. It is shown that the spectrum of the one-particle excitations possesses a gap whose value is connected with the density of particles in the "condensate". At the same time, the pole in the "density-density" Green function determines the phonon-roton spectrum of excitations which exactly coincides with one discovered by Bogolyubov for the collective excitations (the "bogolons").

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V. B. Bobrov, S. A. Trigger, I. M. Yurin. 2009-12-09. Coexistence of the "bogolons" and the one-particle spectrum of excitations with a gap in the degenerated Bose gas. https://doi.org/10.1016/j.physleta.2010.02.075

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