There exist numerous experimental studies of the perpendicular and parallel upper critical magnetic fields in d-wave layered superconductors. They are usually theoretically fitted by the so-called Werthamer, Helfand, and Hohenberg (WHH) results, obtained for an isotropic 3D s-wave superconductors. As was theoretically shown by us and by Bulaevskii, layered compounds are characterized by different ratios of the parameter Hc2(0)/(|dHc2/dT |TcTcTc), where Hc2(0) is the upper critical magnetic field at T = 0 and |dHc2/dT |TcTc), is the so-called Ginzburg–Landau slope near Tc. In this paper, we show that for perpendicular upper critical magnetic field of a d-wave layered superconductor, the above discussed parameter is equal to Hc2(0)/(|dHc2/dT |TcTc) ≈ 0.629. To derive this result, we use exact method of the Green’s functions formulation of the BCS microscopic theory of superconductivity by Gor’kov. We compare our results with experimental ones, obtained on the d-wave superconductor YBa2Cu3O7 – δ.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)