Magnetophonon resonance in high density, high mobility quantum well systems

TL;DR

This study investigates magnetophonon resonance in GaAs quantum wells with AlAs/GaAs superlattices, revealing interactions of electrons with phonons and confirming the presence of X electrons in the system.

Contribution

It provides experimental evidence of two distinct MPR series from Γ and X electrons, clarifying electron-phonon interactions in high mobility quantum well systems.

Findings

Observation of two MPR series from Γ and X electrons.

Confirmation of X electrons in AlAs quantum wells.

Insights into electron-phonon interactions in superlattice structures.

Abstract

We have investigated the magnetophonon resonance (MPR) effect in a series of single GaAs quantum well samples which are symmetrically modulation doped in the adjacent short period AlAs/GaAs superlattices. Two distinct MPR series are observed originating from the $\Gamma$ and X electrons interacting with the GaAs and AlAs longitudinal optic (LO) phonons respectively. This confirms unequivocally the presence of X electrons in the AlAs quantum well of the superlattice previously invoked to explain the high electron mobility in these structures (Friedland et al. Phys. Rev. Lett. 77,4616 (1996).