DYNAMICS OF LOPSIDED ENERGY SHARING BETWEEN A PHOTOELECTRON AND AN AUGER-ELECTRON IN SOLIDS

We study the dynamics of lopsided energy sharing between a photoelectr on and an Auger electron in solids. The problem is formulated as an op tical response theory, in which the energy distribution spectrum for t hese two propagating electrons is expressed in terms of T matrices. In order to perform numerical calculations, we use two different models, which are a partial-wave model and a cubic-lattice model. Firstly, we concentrate on the effect given by the change of the atomic valency f ollowing the Auger decay. As a result, in the former model we have rep roduced the lopsidedness in the peak shifts and distortions of the mai n peaks. Such lopsidedness is realized even in the latter model in spi te of the strong mixing among different partial waves. Furthermore, it should be emphasized that various types of dynamics can occur accordi ng to the local electronic structure around the atom of which core ele ctron is excited. In particular, the energy spectrum of the two electr ons receive modulations representing the local density of states aroun d the initial atom. This is because the phenomenon is essentially loca l in the sense that both the electrons must be inside the Coulomb-pote ntial region of the atom for the energy sharing to occur. Next, we stu dy the effect of electron-electron scattering between the two propagat ing electrons, using a perturbation theory. It is concluded that, when the electron-electron scattering is weak enough, its effect is agains t the previous one and so reduces the lopsidedness in the energy shari ng.