Effect of Electronic Polarization on States of Localized Electrons in Insulators

Starting from the electronic-polaron theory we derive an expression for the interaction between a localized electron and a massive hole via the polarization field for all electron-hole separations. The form of this interaction remains unchanged even when both electron and hole masses are effectively infinite. The expression obtained is compared with the corresponding expression in the Haken-Schottky (HS) theory. Also expressions for polaron effects such as self-energy, mass correction, and Lamb-shift-type corrections are derived in second-order perturbation theory. Owing to the complete analogy between the electron and lattice polarons, our results are also applicable to the case of a bound lattice polaron. Our results are then compared with those of other authors for a bound lattice polaron.