We report Hall measurement of the normal state in K- and Co-doped BaFe2As2, as well NaFe1−xCoxAs. We found that a power-law temperature dependence of Hall angle, cotθH∝Tβ, prevails in normal state with temperature range well above the structural, spin-density-wave and superconducting transitions for the all samples with various doping levels. The power β is nearly 4 for the parent compounds and the heavily underdoped samples, while around 3 for the superconducting samples. The β suddenly changes from 4 to 3 at a doping level that is close to the emergence of superconductivity. It suggests that the β of ∼3 is clearly tied to the superconductivity. Our data suggest that, similar to cuprates, there exists a connection between the physics in the normal state and superconductivity of iron-pnictides. These findings shed light on the mechanism of high-temperature superconductivity.
@article{arxiv.1301.1734,
title = {Power-law Temperature Dependent Hall Angle in the Normal State and its Correlation with Superconductivity in iron-pnictides},
author = {Y. J. Yan and A. F. Wang and X. G. Luo and Z. Sun and J. J. Ying and G. J. Ye and P. Chen and J. Q. Ma and X. H. Chen},
journal= {arXiv preprint arXiv:1301.1734},
year = {2013}
}