Solution of real-axis Eliashberg equations with different pari symmetries and tunneling density of states

Abstract The real-axis direct solution of the Eliashberg equations for the retarded electron-boson interaction in the half-filling case and in the presence of impurities is obtained for six different symmetries of the order parameter: s , s + i d , s + d , d , anisotropic - s and extended - s . The spectral function is assumed to contain an isotropic part α is 2 F(Ω) and an anisotropic one α an 2 F(Ω) such that α is 2 F(Ω) = g·α an 2 F(Ω) , where g is a constant, and the Coulomb pseudopotential μ ∗ is set to zero for simplicity. The density of states is calculated for each symmetry at T = 2, 4, 40 and 80 K. The resulting curves are compared to those obtained by analytical continuation of the imaginary-axis solution of the Eliashberg equations and to the experimental tunneling curves of optimally-doped Bi 2212 crystals.