High harmonics of the cyclotron resonance in microwave transmission of a high-mobility two-dimensional electron system

M L Savchenko,A Shuvaev,A K Bakarov,Z D Kvon,A Pimenov,I A Dmitriev,A A Bykov

doi:10.1103/physrevresearch.3.l012013

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.

Highlights

IntroductionThe discovery of microwave-induced resistance oscillations (MIRO) and zero-resistance states in high-mobility two-dimensional electron systems (2DESs) subject to a moderately strong perpendicular magnetic field [1,2,3] triggered an outbreak of experimental and theoretical research that has led to the observation of a number of interrelated magnetotransport phenomena in various materials and conditions [4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26]
We show that the low-B decay, the magnitude, and polarization dependence of the observed oscillations accurately follow the theoretical predictions of Ref. [29], being governed by a single fitting parameter which describes the broadening of LLs due to impurity scattering
This suggests that the polarization dependence of the measured transmittance |t+|2 and of the dynamic conductivity is well captured by theory [29], as opposed to microwave-induced resistance oscillations (MIRO), where strong deviations were reported for GaAs-based 2DESs [10,49], while a recent experiment with electrons on the surface of liquid He demonstrated a polarization dependence consistent with the theory predictions [20]

Summary

Introduction

The discovery of microwave-induced resistance oscillations (MIRO) and zero-resistance states in high-mobility two-dimensional electron systems (2DESs) subject to a moderately strong perpendicular magnetic field [1,2,3] triggered an outbreak of experimental and theoretical research that has led to the observation of a number of interrelated magnetotransport phenomena in various materials and conditions [4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26]. In application to MIRO, this quantum description is tightly linked to an enhanced absorption of microwave radiation whenever the photon energy hω is close to an integer multiple of the cyclotron energy N hωc [29,31,32,35]. In a nutshell, such enhancements reflect the maxima of the thermally averaged product ν(ε)ν(ε + hω) of initial and final densities of states for transitions between the disorder-broadened LLs. It

Results

Discussion

Conclusion