Abstract
Motivated by recent experiments on isovalent-doped 1111 iron-based superconductors and the theoretical study that followed, we investigate, within the five-orbital model, the correlation between spin fluctuations and the superconducting transition temperature, which exhibits a double-dome feature upon varying the Fe-As-Fe bond angle. Around the first dome with higher , the low-energy spin fluctuation and are not tightly correlated because the finite-energy spin fluctuation also contributes to superconductivity. On the other hand, the strength of the low-energy spin fluctuation originating from the orbital is correlated with in the second dome with lower . These calculation results are consistent with a recent NMR study, and hence strongly suggest that the pairing in iron-based superconductors is predominantly caused by multiorbital spin fluctuations.
- Received 28 January 2015
- Revised 31 March 2015
DOI:https://doi.org/10.1103/PhysRevB.91.134511
©2015 American Physical Society