Measurement of the infrared transmission through a single doped GaAs quantum well in an external magnetic field: Evidence for polaron effects

TL;DR

This study investigates the far-infra-red magneto-transmission of doped GaAs quantum wells under high magnetic fields, revealing polaron effects and new carrier-dependent phonon interactions through experimental and modeling approaches.

Contribution

It provides experimental evidence of polaron effects and introduces a model to quantify carrier-dependent interface phonon interactions in doped GaAs quantum wells.

Findings

Observation of polaronic effects due to LO phonons.

Detection of a new carrier concentration dependent interaction with interface phonons.

Use of a multilayer dielectric model to simulate transmission spectra.

Abstract

Precise absolute far-infra-red magneto-transmission experiments have been performed in magnetic fields up to 33 T on a series of single GaAs quantum wells doped at different levels. The transmission spectra have been simulated with a multilayer dielectric model. The imaginary part of the optical response function which reveals new singular features related to the electron-phonon interactions has been extracted. In addition to the expected polaronic effects due to the longitudinal optical (LO) phonon of GaAs, a new kind of carrier concentration dependent interaction with interface phonons is observed. A simple physical model is used to try to quantify these interactions and explore their origin.