Осцилляции Шубникова-де Гааза в двумерном электронном газе с анизотропной подвижностью

Abstract

Abstract Shubnikov de Haas oscillations in selectively doped GaAs single quantum wells with AlAs/GaAs superlattice barriers has been studied at temperature T = 4.2 K in magnetic fields B < 1 Т. High-mobility heterostructures with thin spacer had been grown by molecular-beam epitaxy on (001) GaAs substrates. The mobilities of two-dimensional electron gas measured in two crystallographic directions [110] and [-110] differ from each other more than 50%. Properly adapted expression for Shubnikov de Haas oscillations amplitudes in anisotropic samples has been used for correct analysis of this oscillations. It was stated that quantum life-time in our heterostructures as measured by Shubnikov de Haas oscillations on Hall bars oriented in the directions [110] and [-110] varies less than 5%. Obtained results show that quantum life-time in two-dimensional electron system with anisotropic mobility is isotropic with aforementioned accuracy.