Superfluid Bose Liquid with a Suppressed BEC and an Intensive Pair Coherent Condensate as a Model ofH4e

Abstract

One introduces a model of the superfluid state of a Bose liquid with repulsion between bosons, in which at T=0, along with a weak single-particle Bose-Einstein condensate, there exists an intensive pair coherent condensate, analogous to the Cooper condensate in a Fermi liquid with attraction between fermions. A closed system of nonlinear integral equations for the normal and anomalous self-energy parts is solved numerically, and a quasiparticle spectrum is obtained, which is in good agreement with the experimental spectrum of elementary excitations in superfluid 4He. It is shown that the roton minimum in the spectrum is associated with the negative minimum of the Fourier component of the pair interaction potential.

Converting boson–fermion mixtures

“…Even at temperatures well below T c the condensed state is fundamentally different from the MFA ground state, because of the pairing of bosons. The latter is similar to the Cooper-like pairing of supracondensate 4 He atoms [27], proposed as an explanation of the small density of the single-particle Bose condensate in superfluid Helium-4. The pair-boson condensate should significantly modify the thermodynamic properties of the condensed BFM compared with the MFA predictions.…”

Excitations of Metastable SuperfluidH4eat Pressures Up to 40 Bars

“…5 at SVP [14] to 2% at 25 bars and to less than 1% at 40 bars [15,16]. It is not known whether the above ideas all remain true in the metastable liquid when n 0 becomes extremely small [17,18], and whether effects of a very small condensate can be observed in the PR excitations. Also, in PM, the ''normal'' liquid above T c but below T has been shown to contain localized BEC (local phase coherence) [10,11,19].…”

Exponentially Correlated Gaussians for Simulating Of Localized and Autolocalized States in Polar Media

“…Изучение парного потенциала бозе-частиц необходимо для корректного описания фазового перехода бозе-системы в состояния сверхтекучести (нейтральные бозе-частицы) и сверхпроводимости (заряженные частицы, например биполяронный газ) [41,42].…”