A unified microscopic theory of superfluidity and superconductivity

A consistent and unified microscopic theory of a novel two-stage Fermi-Bose liquid (FBL) scenarios of superfluidity and superconductivity is developed as a combined theory of Fermi- and superfluid (SF) Bose-liquid. Modified and generalized BCS like pairing theory of fermions is presented. In analogy to that a detail boson pairing theory is developed. The single particle (SPC) and pair condensation (PC) features of an attracting 3d- and 2d-Bose gas as a function of the interboson coupling constant in the complete range 0 ≤ T ≤ Tc is studied in detail. It is shown that such SPC and PC of an attracting composite bosons (Cooper pairs, bipolarons, holons, 4He atoms, deuterons, alpha particles) lies on the basis of superfluidity both in Fermi and Bose systems. It is argued that the coexistence of the order parameters of attracting fermions ΔF and bosons ΔB leads to the superfluidity and superconductivity by two FBL scenarios. One of these scenarios is realized in so-called fermion superconductors (FSC) and other -in boson one (BSC) in which the gapless superconductivity is caused by absence of the gap ΔSF in the excitation spectrum of bosons and not by presence of point or line nodes of the BCS-like gap ΔF. The new adequate determination for basic superconducting parameters of FSC and BSC are given. The necessary and sufficient microscopic criterions for a superfluidity is formulated. The theory proposed is consistent with the different experimental data available in 4He, 3He, superconductors, nucleis, neutron stars and others. (author). 133 refs, 14 figs