1207.2221 (L. A. Wray et al.)

Deviant band symmetries and many-body interactions in a model hole doped
iron pnictide superconductor    [PDF]

L. A. Wray, R. Thomale, C. Platt, D. Hsieh, D. Qian, G. F. Chen, J. L. Luo, N. L. Wang, M. Z. Hasan

We present a polarization resolved study of the low energy band structure in the optimally doped iron pnictide superconductor Ba$_{0.6}$K$_{0.4}$Fe$_2$As$_2$ (T$_C$=37K) using angle resolved photoemission spectroscopy. Polarization-contrasted measurements are used to identify and trace all three low energy hole-like bands predicted by local density approximation (LDA) calculations. The photoemitted electrons reveal surprising inconsistencies with LDA-predicted symmetries and kinetics along both $\Gamma$-X and $\Gamma$-M high symmetry momentum axes. We evaluate many-body effects such as Mott-Hubbard interactions that are likely to underlie the anomalies, and discuss how the observed deviations from LDA band structure affect the energetics of iron pnictide Cooper pairing in the hole doped regime.

View original: http://arxiv.org/abs/1207.2221