Performing the first-principles calculations, we investigate the anisotropy in the superconducting state of iron-based superconductors to gain an insight into their potential applications. The anisotropy ratio γλ of the c-axis penetration depth to the ab-plane one is relatively small in BaFe2As2 and LiFeAs, i.e., γλ∼3, indicating that the transport applications are promising in these superconductors. On the other hand, in those having perovskite type blocking layers such as Sr2ScFePO3 we find a very large value, γλ∼200, comparable to that in strongly anisotropic high-Tc cuprate Bi2Sr2CaCu2O{8-\delta}. Thus, the intrinsic Josephson junction stacks are expected to be formed along the c-axis, and novel Josephson effects due to the multi-gap nature are also suggested in these superconductors.
@article{arxiv.0910.0107,
title = {First-Principles Study for the Anisotropy of Iron-based Superconductors toward Power and Device Applications},
author = {Hiroki Nakamura and Masahiko Machida and Tomio Koyama and Noriaki Hamada},
journal= {arXiv preprint arXiv:0910.0107},
year = {2015}
}