The Superfluid State of a Bose Liquid as a Superposition of a Suppressed Bose-Eistein Condensate and an Intensive Pair Coherent Condensate
| dc.creator | Pashitskii, E. A. | |
| dc.creator | Mashkevich, S. V. | |
| dc.creator | Vilchynskyy, S. I. | |
| dc.date | 2002-08-19 | |
| dc.date.accessioned | 2026-07-07T02:46:53Z | |
| dc.date.available | 2026-07-07T02:46:53Z | |
| dc.description | A self-consistent model of the superfluid (SF) state of a Bose liquid with strong interaction between bosons is considered, in which at T=0, along with a weak single-particle Bose-Einstein condensate (BEC), there exists an intensive pair coherent condensate (PCC) of bosons, analogous to the Cooper pair condensate of fermions. Such a PCC emerges due to an effective attraction between bosons in some regions of momentum space, which results from an oscillating sign-changing momentum dependence of the Fourier component V(p) of the interaction potential. The collective many-body effects of renormalization ("screening") of the initial interaction, which are described by the bosonic polarization operator Π(p,ω), lead to a suppression of the repulsion [V(p)>0] and an enhancement of the effective attraction [V(p)<0] in the respective domains of nonzero momentum transfer. The ratio of the BEC density n_0 to the total particle density n of the Bose liquid is used as a small parameter of the model. A closed system of nonlinear integral equations for the normal and anomalous self-energy parts is obtained with account for the terms of first order in the BEC density. In the framework of the ``soft spheres'' model with the single fitting parameter--the value of the repulsion potential at r=0, a theoretical quasiparticle spectrum E(p) is obtained, which is in good accordance with the experimental spectrum E_{exp}(p) of elementary excitations in superfluid $^4$He. | |
| dc.description | 32 pages, 11 figures, LATEX | |
| dc.identifier | https://arxiv.org/abs/cond-mat/0208350 | |
| dc.identifier | http://arxiv.org/abs/cond-mat/0208350 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/19800 | |
| dc.subject | Soft Condensed Matter | |
| dc.title | The Superfluid State of a Bose Liquid as a Superposition of a Suppressed Bose-Eistein Condensate and an Intensive Pair Coherent Condensate | |
| dc.type | text |