Fig. 3: Doping effects on the critical temperature in different approaches.
From: Full-bandwidth anisotropic Migdal-Eliashberg theory and its application to superhydrides
Effects of doping (shifting the Fermi level) in H3S at 200 GPa (panels (a, b)) and BaSiH8 at 30 GPa (panels (c, d)). Panel (a) shows the superconducting critical temperature Tc as a function of the Fermi level shift ΔεF, obtained within the mMc formula (green), the UF equation (orange), the FSR approximation (blue), and the FBW approach (red). The smaller subpanels on top show the corresponding DOS in a range of ± 2 eV around the unshifted Fermi energy εF, where the dashed lines mark the position of εF + ΔεF and the shaded red areas highlight the included electronic energy range of εF + ΔεF ± 1 eV. Panel (b) displays the distribution of the values of the anisotropic superconducting gap Δnk on the Fermi surface within the FSR (blue) and FBW (red) approach for H3S with ΔεF = −0.1 eV, where we find the maximum absolute difference between the FSR and FBW Tc (see blue and red lines in (a)). The inset shows the corresponding DOS subpanel from (a). Panels (c, d) show the corresponding results for BaSiH8 at 30 GPa, where we find the maximum Tc difference for ΔεF = +0.1 eV.
