Circular dichroism in photoinduced Auger decay

Abstract

It is demonstrated that the angular distribution of Auger electrons produced in photoionization of non-polarized atoms by circularly polarized light is different for left and right circular polarization, provided the Auger electron is detected in coincidence with the photoelectron ejected in a certain direction. A general formulation of the theory of circular dichroism in angular-resolved double photoionization is presented based on the statistical tensor formalism. Extreme cases of direct and two-step double photoionization are considered and the inherent similarities and differences between the two cases as applied to circular dichroism are discussed. As an example, photoionization in the 3p₃2/ subshell of Ca and the following M₃-N₁N₁ Auger transition is considered. The connection of the dichroism in the angular distribution of Auger electrons to the photoelectron spin polarization is discussed as well as their dependence on the dynamical properties of photoionization amplitudes.