1999/01/21 by A. Yu. Cherny, Alexander Yu. Cherny, A. A. Shanenko · 1 citation
Physics and Astronomy · #Physics of Superconductivity and Magnetism #Quantum and electron transport phenomena #Rare-earth and actinide compounds #cond-mat.stat-mech #cond-mat.supr-con
paper · pdf · doi:10.1103/physrevb.60.1276
published as Phys. Rev. B 60 (1999) 1276. · REVTeX, 8 pages, no figures, submitted to Phys. Rev. B
arxiv created 1999/01/21 · openalex publication_date 1999/07/01 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
As is known, the 1/q2 theorem of Bogoliubov asserts that the mean density of the fermion pair states with the total momentum q obeys the inequality nq>~C/q2(\stackrel\ensuremath→q0) in the case of the Fermi system taken at nonzero temperature and in the superconducting state provided the interaction term of its Hamiltonian is locally gauge invariant. With the principle of correlation weakening it is proved in this paper that the reason for the mentioned singular behavior of nq is the presence of the bound states of particle pairs with nonzero total momenta. Thus, below the temperature of the superconducting phase transition there always exist the bound states of the fermion couples beyond the pair condensate. If the pseudogap observed in the normal phase of the high-Tc superconductors is stipulated by the presence of the electron bound pairs, then the derived result suggests, in a model-independent manner, that the pseudogap survives below Tc.