Magnetic Circular Dichroism of Resonant X-Ray Emission Spectra by Electric Quadrupole Excitation

抄録

We give a theoretical prediction for the angle dependence of the magnetic circular dichroism in resonant X-ray emission spectroscopy (MCD-RXES) by the electric quadrupole excitation. After general analytic calculations with an atomic model, we perform numerical calculations of L_2,3–M_4,5 MCD-RXES for Sm³⁺, where the 2p–4f electric quadrupole excitation, as well as the 2p–5d electric dipole excitation, is followed by the 3d–2p X-ray emission by the electric dipole transition. Tuning the incident X-ray energy in the pre-edge region of the L₃ X-ray absorption, the change of the spectral shape of MCD-RXES is studied in detail with the change of the incident and emitted X-ray angles. We also discuss the possibility of detecting the signal of the electric quadrupole excitation in the MCD-RXES spectra, separately from that of the electric dipole excitation, by changing the incident and emission angles.