Pseudogap in non-superconducting pnictides, CaFe$_2$As$_2$ and EuFe$_2$As$_2$

Superconductivity in Fe-pnictides are studied extensively recently as they provide a non-cuprate domain to study unconventional superconductivity via doping induced suppression of magnetism. In order to study the role of magnetic interactions in the electronic structure and its implication in superconductivity, we probed the electronic structure of the parent compounds CaFe$_2$As$_2$ and EuFe$_2$As$_2$ using high resolution photoemission spectroscopy. Single crystalline samples were prepared by flux method. Photoemission measurements were carried out using a Gammadata Scienta analyzer R4000 and monochromatic photon sources. The high resolution spectra exhibit signature of a pseudogap above the spin density wave (SDW) transition temperature in both CaFe$_2$As$_2$ and EuFe$_2$As$_2$. The intensity at the Fermi level show a sudden decrease across the SDW transition indicating more prominent pseudogap. An additional gap opens up in EuFe$_2$As$_2$ across the antiferromagnetic transition temperature as expected. Interestingly, CaFe$_2$As$_2$ also exhibit signature of another gap opening at low temperatures although no phase transitions observed in this temperature range.