Microwave photoresponse in the 2D electron system caused by intra-Landau level transitions

TL;DR

This paper investigates how microwave radiation affects the magnetoresistance of 2D electron systems, revealing non-equilibrium electron distributions caused by intra-Landau level transitions that influence resistance behavior.

Contribution

It demonstrates the role of microwave-induced intra-Landau level transitions in modifying the resistance and oscillations in 2D electron systems under magnetic fields.

Findings

Microwave radiation below 30 GHz suppresses resistance over a wide magnetic field range.

Higher frequencies cause non-monotonic damping of Shubnikov-de Haas oscillations.

Non-equilibrium electron distributions are created by intra-Landau level transitions.

Abstract

The influence of microwave radiation on the DC-magnetoresistance of 2D-electrons is studied in the regime beyond the recently discovered zero resistance states when the cyclotron frequency exceeds the radiation frequency. Radiation below 30 GHz causes a strong suppression of the resistance over a wide magnetic field range, whereas higher frequencies produce a non-monotonic behavior in the damping of the Shubnikov-de Haas oscillations. These observations are explained by the creation of a non-equilibrium electron distribution function by microwave induced intra-Landau level transitions.