Comment on "Violation of Anderson's Theorem for the sign-reversing s-wave state of Iron-Pnictide Superconductors" by Onari et al., Phys. Rev. Lett. 103, 177001(2009)[1]

TL;DR

This paper critiques a previous claim about impurity effects in Iron-based superconductors, showing that similar results can be obtained with different models, thus challenging the necessity of orbital degrees of freedom in this context.

Contribution

It demonstrates that impurity effects on Tc suppression are consistent across band and orbital basis models, countering prior assertions about the importance of orbital degrees of freedom.

Findings

Impurity-induced Tc suppression is similar in both models

Orbital degrees of freedom are not essential for describing impurity effects

Challenges previous claims about the necessity of orbital considerations

Abstract

We pointed out that the main claim of Ref.[1] that the presence of the orbital degree of freedom is essential to describe the correct impurity effects for Iron-based superconductors is incorrect and demonstrated the equivalent results of Tc suppression due to impurities by both the band basis model and the orbital basis model.