Raman scattering study of spin-density-wave-induced anisotropic   electronic properties in AFe2As2 (A=Ca,Eu)
  We present a polarization-resolved and temperature-dependent Raman scattering study of AFe2As2 (A = Ca, Eu). In the spin-density-wave (SDW) phase, spectral weight redistribution is observed in the fully symmetric and non-symmetric scattering channels at different energies. An anisotropic Raman response is observed in the fully symmetric channel in spontaneously detwinned CaFe2As2 samples. We calculate the orbital-resolved electronic structures using a combination of density functional theory and dynamical mean field theory (DFT+DMFT). 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 dxz/yz orbitals in the broken symmetry phase. 
W.-L. Zhang, Z. P. Yin, A. Ignatov, Z. Bukowski, Janusz Karpinski,   Athena S. Sefat, H. Ding, P. Richard, and G. Blumberg
cond-mat.str-el