If strong electron-electron interactions between neighboring Fe atoms mediate the Cooper pairing in iron-pnictide superconductors, then specific and distinct anisotropic superconducting energy gaps \Delta_i(k) should appear on the different electronic bands i. Here we introduce intra-band Bogoliubov quasiparticle scattering interference (QPI) techniques for determination of \Delta_i(k) in such materials, focusing on LiFeAs. We identify the three hole-like bands assigned previously as \gamma, \alpha_2 and \alpha_1, and we determine the anisotropy, magnitude and relative orientations of their \Delta_i(k). These measurements will advance quantitative theoretical analysis of the mechanism of Cooper pairing in iron-based superconductivity.
@article{arxiv.1205.2673,
title = {Anisotropic Energy Gaps of Iron-based Superconductivity from Intra-band Quasiparticle Interference in LiFeAs},
author = {M. P. Allan and A. W. Rost and A. P. Mackenzie and Yang Xie and J. C. Davis and K. Kihou and C. H. Lee and A. Iyo and H. Eisaki and T. -M. Chuang},
journal= {arXiv preprint arXiv:1205.2673},
year = {2012}
}