Quantum oscillations in the microwave magnetoabsorption of a 2D electron gas

TL;DR

This paper reports the experimental detection of quantum oscillations in microwave magnetoabsorption of a high-mobility 2D electron gas, confirming theoretical predictions and explaining previous experimental discrepancies.

Contribution

It introduces a novel resonance-cavity technique to observe quantum oscillations from inter- and intra-Landau-level transitions in 2D electron gases.

Findings

Quantum oscillations observed match theoretical predictions.

Oscillations originate from inter- and intra-Landau-level transitions.

The theory explains absence of similar oscillations in transmission and reflection experiments.

Abstract

We report on the experimental observation of the quantum oscillations in microwave magnetoabsorption of a high-mobility two-dimensional electron gas induced by Landau quantization. Using original resonance-cavity technique, we observe two kinds of oscillations in the magnetoabsorption originating from inter-Landau-level and intra-Landau-level transitions. The experimental observations are in full accordance with theoretical predictions. Presented theory also explains why similar quantum oscillations are not observed in transmission and reflection experiments on high-mobility structures despite of very strong effect of microwaves on the dc resistance in the same samples.