Pekar mechanism of electron-phonon interaction in nanostructures

We demonstrate that in nanostructures an additional mechanism of electron-acoustic phonon interaction has to be considered along with traditional mechanisms. It was addressed previously by Pekar for bulk crystals with extremely high dielectric permittivity. The additional coupling is due to macroscopic electrical potential which is caused by modulation of the dielectric permittivity by a phonon in the presence of external electric field. We show that in nanostructures this mechanism is important because of strong confining electric fields. In this case both absolute value and spatial distribution of the electric field influence strength of interaction. We consider two specific examples where Pekar interaction is important: low-temperature energy relaxation of 2D-electrons in silicon inversion layers and phonon emission from nitride multiple quantum well structures.