We report on orbital-dependent quasiparticle dynamics in EuFe2As2, a parent compound of Fe-based superconductors and a novel way to experimentally identify this behavior, using time- and angle-resolved photoelectron spectroscopy across the spin density wave transition. We observe two different relaxation time scales for photo-excited dxz/dyz and dxy electrons. While dxz/dyz electrons relax faster through the electron-electron scattering channel, showing an itinerant character, dxy electrons form a quasi-equilibrium state with the lattice due to their localized character, and the state decays slowly. Our findings suggest that electron correlation in Fe-pnictides is an important property, which should be taken into careful account when describing the electronic properties of both parent and electron-doped compounds, and therefore establish a strong connection with cuprates.
@article{arxiv.1711.05464,
title = {Orbital-dependent electron dynamics in Fe-pnictide superconductors},
author = {Ganesh Adhikary and Barbara Ressel and Matija Stupar and Primož Rebernik Ribič and Jurij UrbančIč and Giovanni De Ninno and D. Krizmancic and A. Thamizhavel and Kalobaran Maiti},
journal= {arXiv preprint arXiv:1711.05464},
year = {2018}
}