the renormalization function Z(k,iω_n ) effects on the λ and the Tc

[xiaming]

Dear sir

We know that anisotropic Eliashberg equations are composed of the superconducting gap Δ(k,iω_n ), the renormalization function Z(k,iω_n ), the EPC λ, and the Temperature T. Can anyone tell me how the renormalization function Z(k,iω_n ) effects on the λ and the Tc ? I find some materials have a large λ but a low Tc. Does it because the mass renormalization dominate in these system ? And how it acts on the λ and the Tc ? Are there some references about how to do with this problem? Or maybe some approaches to solve this ? Can you share to me ? Thank you very much!

Best wishes!