# Effect of density on microwave-induced resistance oscillations in back-gated GaAs quantum wells

## TL;DR

This study investigates how carrier density influences microwave-induced resistance oscillations in GaAs quantum wells, revealing discrepancies with existing theories and highlighting the need for further research.

## Contribution

It provides new experimental insights into the density dependence of MIROs in GaAs quantum wells, challenging current theoretical models.

## Key findings

- MIRO amplitude increases with density
- Oscillation extrema shift towards cyclotron resonance with density
- Existing theories do not fully explain the observed behavior

## Abstract

We report on microwave-induced resistance oscillations (MIROs) in a tunable-density 30-nm-wide GaAs/AlGaAs quantum well. We find that the MIRO amplitude increases dramatically with carrier density. Our analysis shows that the anticipated increase in the effective microwave power and quantum lifetime with density is not sufficient to explain the observed growth of the amplitude. We further observe that the fundamental oscillation extrema move towards cyclotron resonance with increasing density, which also contradicts theoretical predictions. These findings reveal that the density dependence is not properly captured by existing theories, calling for further studies.