Solution of real-axis Eliashberg equations with different pair 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: $s$, $s+\mathrm{i}d$, $s+d$, $d$, anisotropic-$s$ and extended-$s$. The spectral function is assumed to contain an isotropic part ${\alpha }_{is}^{2}F(\Omega )$ and an anisotropic one ${\alpha }_{an}^{2}F(\Omega )$ such that ${\alpha }_{is}^{2}F(\Omega )=g\cdot {\alpha }_{an}^{2}F(\Omega )$, where $g$ is a constant, and the Coulomb pseudopotential ${\mu }^{\ast }$ 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.

M2S-HTSC-VI Conference paper (2 pages, 1 figure), using Elsevier style espcrc2.sty