Observation of Dirac Cone Electronic Dispersion in BaFe$_{2}$As$_{2}$

As with cuprates, it is widely believed that high-$T_{c}$ superconductivity in pnictides emerges by tuning interactions already present in the parent compounds and it is thus imperative to understand their electronic structure. We performed an angle-resolved photoemission spectroscopy study of BaFe$_{2}$As$_{2}$, which is the parent compound of the so-called $122$ phase of the iron-pnictide high-temperature superconductors. We reveal the existence of a Dirac cone in the electronic structure of this material below the spin-density-wave temperature, which is responsible for small spots of high photoemission intensity at the Fermi level. Our analysis suggests that the cone is slightly anisotropic and its apex is located very near the Fermi level, leading to tiny Fermi surface pockets. Moreover, the bands forming the cone show an anisotropic leading edge gap away from the cone that suggests a nodal spin-density-wave description.