Observation of High Harmonics of the Cyclotron Resonance in Microwave Transmission of a High-Mobility Two-Dimensional Electron System

TL;DR

This study observes high harmonic cyclotron resonance effects in microwave transmission through a high-mobility 2D electron system, revealing enhanced absorption and providing insights into high-frequency transport phenomena.

Contribution

It demonstrates the detection of high harmonic cyclotron resonance in microwave transmission and links it to microwave-induced resistance oscillations, advancing understanding of high-frequency transport in 2D systems.

Findings

Observation of magnetooscillations in transmitted microwave power

Correlation between transmittance oscillations and MIRO

Validation of photon-assisted scattering theory

Abstract

We report an observation of magnetooscillations of the microwave power transmitted through the high mobility two-dimensional electron system hosted by a GaAs quantum well. The oscillations reflect an enhanced absorption of radiation at high harmonics of the cyclotron resonance and follow simultaneously measured microwave-induced resistance oscillations (MIRO) in the dc transport. While the relative amplitude (up to 1%) of the transmittance oscillations appears to be small, they represent a significant (>50%) modulation of the absorption coefficient. The analysis of obtained results demonstrates that the low-B decay, magnitude, and polarization dependence of the transmittance oscillations accurately follow the theory describing photon-assisted scattering between distant disorder-broadened Landau levels. The extracted sample parameters reasonably well describe the concurrently measured MIRO. Our results provide an insight into the MIRO polarization immunity problem and pave the way to probe diverse high-frequency transport properties of high-mobility systems using precise transmission measurements.