Electron locking in semiconductor superlattices

TL;DR

This paper introduces a new electron-phonon state in semiconductor superlattices characterized by electron self-trapping and phonon localization, especially enhanced by magnetic fields, with analytic models and experimental suggestions.

Contribution

It presents a novel theoretical description of self-trapped electron-phonon states in superlattices, including analytic expressions and potential experimental detection methods.

Findings

Identification of self-trapped electron states in SSL

Analytic expressions for strong coupling regimes

Enhanced effects in magnetic fields

Abstract

We describe a novel state of electrons and phonons arising in semiconductor superlattices (SSL) due to strong electron-phonon interactions. These states are characterized by a localization of phonons and a self-trapping or locking of electrons in one or several quantum wells due to an additional, deformational potential arising around these locking wells in SSL. The effect is enhanced in a longitudinal magnetic field. Using the tight-binding and adiabatic approximations the whole energy spectrum of the self-trapped states is found and accurate, analytic expressions are included for strong electron-phonon coupling. Finally, we discuss possible experiments which may detect these predicted self-trapped states.