Pressure dependence of the cyclotron mass in n-GaAs-GaAlAs heterojunctions by FIR emission and transport experiments

Abstract

The pressure dependence of the cyclotron mass of quasi-twodimensional electrons in GaAs-GaAIAs heterojunctions is studied. We use cyclotron emission experiments coupled with transport experiments. An increase of 0.5% per kbar of t h e cyclotron mass is found in t h e investigated pressure range W3 kbar. Our analysis shows that two effects, which act in opposite directions, must be considered: the first is the increase of t h e mass due to the increase of the energy gap and the second is the reduction of the non-parabolicity corrections due to the decrease of t h e two-dimensional electron gas density when pressure is applied. This explains that t h e observed increase of the cvclotron mass is smaller than the one predicted by t h e kp perturbation method

Charge transfer and electron mobility in GaAlAs/GaAs modulation-doped heterostructures: the role of interface states

“…In the calculations of the mobility we have neglected the non-parabolicity effect. For the samples with the lowest 2DEG density (N s ≤ 2 × 10 11 cm −2 ) this effect is negligible, and for the samples with the highest values of N s (N s 4.5×10 11 cm −2 ) the relative decrease of the mobility is less than 10% [18,19]. Nevertheless, the decrease of the theoretical mobility due to the non-parabolicity is, for all the samples, much less than the disagreement between the theoretical and experimental values and cannot explain the discrepancy between both values of the mobility.…”

In situ Characterization during MOCVD

“…The Hall density slightly decreases with increasing temperature. An analysis of the emission spectra allows us to determine, for example, the cyclotron mass of the 2D electrons [Chaubet et al 1991], the amount and the position of impurities in the quantum well [Gornik et al 1987, Robert et al 1988, Knap et al 1990, and to study the polaron effects ]. The most striking point is the very high critical temperature at which the PPC is suppressed.…”

Plasma wave oscillations in nanometer field effect transistors for terahertz detection and emission

“…Experimental investigation of THz emission from nanotransistors was performed with two experimental systems: a cyclotron resonance spectrometer [3,19] and a Fourier transform spectrometer equipped with an ultra-sensitive bolometer [5]. The cyclotron resonance spectrometer was used earlier to investigate a weak THz cyclotron resonance emission in GaAs/AlGaAs heterojunctions [20]. In this spectrometer, the THz source and detector under study are placed in a copper waveguide, cooled to 4.2 K and completely isolated from 300 K background radiation.…”