Abstract
We present a polarization-resolved and temperature-dependent Raman scattering study of A Fe sub(2) As sub(2)(A=Ca, Eu). In the spin-density-wave phase, spectral weight redistribution is observed in the fully symmetric and nonsymmetric scattering channels at different energies. An anisotropic Raman response is observed in the fully symmetric channel in spontaneously detwinned CaFe sub(2) As sub(2) samples. We calculate the orbital-resolved electronic structures using a combination of density functional theory and dynamical mean field theory. We identify the electronic transitions corresponding to these two spectral features and find that the anisotropic Raman response originates from the lifted degeneracy of the d sub()xzyzorbitals in the broken-symmetry phase.