Evidence for magnetoplasmon character of the cyclotron resonance response of a two-dimensional electron gas

TL;DR

This study provides experimental evidence that the cyclotron resonance response in high-density, high-mobility GaAs quantum wells is best described by a magnetoplasmon model, highlighting the importance of many-body effects in interpreting infrared spectroscopy data.

Contribution

The paper demonstrates that magnetoplasmon theory accurately explains non-linear features in cyclotron resonance energies and oscillator strengths in 2D electron gases.

Findings

Magnetoplasmon theory matches experimental magneto-transmission data.

Cyclotron resonance energies show non-linear magnetic field dependence.

Oscillator strengths are influenced by many-body magnetoplasmon excitations.

Abstract

Experimental results on the absolute magneto-transmission of a series of high density, high mobility GaAs quantum wells are compared with the predictions of a recent magnetoplasmon theory for values of the filling factor above 2. We show that the magnetoplasmon picture can explain the non-linear features observed in the magnetic field evolution of the cyclotron resonance energies and of the absorption oscillator strength. This provides experimental evidence that inter Landau level excitations probed by infrared spectroscopy need to be considered as many body excitations in terms of magnetoplasmons: this is especially true when interpreting the oscillator strengths of the cyclotron transitions.