High-temperature superconductivity in two-band materials with interband pairing
National Research Nuclear University, Moscow
Engineering Physics Institute, Kashirskoe sh.31, 115409
Published online: 10 June 2015
Eliashberg theory is generalized with account of the specific properties of two-band electron-phonon (EP) systems. The superconducting transition temperature Tc is examined in two-band materials, one of the representatives of which are pnictides. The strong EP coupling and the pairing within the full width of the electron band and not only in a narrow region near the Fermi surface are taken into account. It is found that the effect of the pairing of electrons belonging to different bands is crucial to the appearance of high Tc in these materials. It is shown that the high Tc value in the materials, such as pnictides, is displayed with the use of a two-band spectral function of the EP interaction derived from calculations and from tunnel experiments. The existence of specific conditions for the high Tc appearance in the two-band materials is established.
Key words: Solid State and Materials
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2015