Nonlinear effects in 2D electron gas in GaAs/GaAlAs heterostructures in millimeter range

摘要

Abstract: The results of the investigation of two-dimensional electron gas (2DEG) using millimeter spectroscopy technique are presented. The measurements in the millimeter region allow us to register cyclotron resonance (CR) and Shubnikov-de-Haas (SdH) oscillations of electron gas in the same time. This spectral region is optimal to study the electron heating effects also. The main attention is focused on the investigations of the magnetospectra of photocurrent, photoconductivity, transmission and differential transmission of the electron system in 2DEG of GaAs/GaAlAs heterostructures using cyclotron resonance (CR) technique. The investigations of GaAs/AlGaAs heterostructures by photoconductivity technique have shown that the magnetospectra have the complex structure (even with the change of the photocurrent polarity). The magnetospectra depend on frequency and polarization of the incident radiation. The radical changes of the CR-line and the SdH oscillations at the reversion of the magnetic field direction are discovered. The discovered effects are very promising for the development of heterostructures diagnostics methods. These effects reveal a possibility to elaborate solid state detectors to analyze the parameters of millimeter and submillimeter waves. In the study of GaAs/AlGaAs heterostructures with high mobility in pulsed electric field up to 100 V/cm we have discovered an increase of transmission in the center of the CR line. The connection of this phenomenon with collective effects such as the hot electron resonant bunching in the momentum space at non-elastic scattering by optical phonons is discussed. !28