Electronic anisotropy in Ba(Fe$_{1-x}$Ru$_{x})_{2}$As$_{2}$ revealed by ARPES

One of the central issues in field of iron pnitides is the origin of electronic anisotropy observed by in-plane resistivity measurement and STM quasi-particle interference patterns. It is believed that it is related to magnetism and plays an important role in superconductivity in iron pnictides. It was argued that the split bands in ARPES data are from two orthogonal bands with dominant d$_{xz}$ and d$_{yz}$ characters, demonstrating the in-plane electronic anisotropy. It appears to be consistent with anisotropy observed by other probes. We performed temperature dependent ARPES measurements on an iron pnictide system, Ba(Fe$_{1-x}$Ru$_{x})_{2}$As$_{2}$, to experimentally verify existence of electronic anisotropy and compare the results with those of BaFe$_{2}$As$_{2}$ and Ba(Fe$_{1-x}$Co$_{x})_{2}$As$_{2}$.