The Study Of Magnetic Transport Properties Of Two-Dimensional Electron Gases For Ingaas/InAlAs Quantum Wells

InGaAs/InAlAs is one of the best materials of high electron mobility transistor (HEMT) up to now. The research about InGaAs/InAlAs is just unfolding. The study of transport properties in deep low temperature and strong magnetic field may provide an important reference for improving the performance of devices. This paper reported on magnetic transport properties in deep low temperature and strong magnetic field conditions for InGaAs/InAlAs samples. We studied the parameters of electron density, effective mass, mobility, spin orbit coupling coefficient and effective g factor. The following conclusions were obtained.1. The different effect on electron mobility have been studied under different conditions. In the transport test with the changes of temperatures and magnetic field, the electron effective mass was obtained, and the change rule of transport mobility and quantum mobility with temperature changing were studied. In the temperature range from1.4K to6K, with temperature rising, the electron concentration and the transport mobility changed little, electron concentration increased slightly, transport mobility decreased slightly, quantum mobility reduced much, and the decrease of quantum mobility was linear. At the same time, the quantum mobility was much smaller than the transport mobility. The transport mobility was about7to8times more than the quantum mobility. So the small angle scattering dominated in the scattering mechanism of the sample. In the tilted field, we also verified that the Hall mobility and quantum mobility was not affected by the angles between magnetic field and the normal of sample plane.2. We studied the spin splitting of the sample. Under the condition of variable temperatures, we found the beating nodes occur obviously at the temperature of T=1.4K,1.7K,2.9K and4.0K in the SdH oscillation. The beating nodes did not move with the temperature changing. The amplitudes weakened with temperature rising, and, when the temperature rose to6.0K, the beating phenomenon could not be observed. We also discovered two peaks structure in the FFT spectrum. By means of the analysis of the two peaks, we found it is caused by the spin splitting. As expected, we found the zero field spin splitting energy and Rashba coefficient changed little with the changing of temperatures. At the same time, the effective g factor of the sample was studied in the tilted field transport test. We analyzed the changes of the beating nodes with different angles between the total magnetic field and its vertical component. With the increasing of angles the beating nodes moved to higher field. By fitting the curves of the vertical component of total magnetic field corresponding to the nodes as a function of the cosine of Angles, the effective g factor and zero field spin splitting for the samples were obtained.