Electrodynamical treatment of the electron-hole long-range exchange interaction in semiconductor nanocrystals

We show that the contribution to the fine structure of the ground exciton level in a semiconductor nanocrystal due to the long-range part of the electron-hole exchange interaction can be equivalently described as arising from the mechanical exciton interaction with the exciton-induced macroscopic longitudinal electric field. Particular cases of nanocrystals with cubic and wurtzite crystal lattice in the strong confinement regime are studied taking into account the complex structure of the valence band. A simplified model accounting for the exciton ground-level splitting and exploiting an effective local scalar susceptibility is established.