Transport Research Of Two Dimensional Electron Gas At Hypothermia

In the early80s last century, the discovery of quantum Hall effect (QHE) in the2DEG under the cryogenic temperature developed a wholly new research domain, eg. Quantum transport in the condensed matter physics. In the past30years, it achieved a great achievement. In the system of2DEG,the occurrence of orbital quantization, disorder, electron-electron interaction and novel magnetoresistance oscillatory (MO) makes the research of QHE colorful.The quantum transport in2DEG is an important topic in the condensed matter physics. This thesis begins with the fundamental relevant theory, briefly introduces the basic knowledge and concepts about the unique performance in2DEG. The magnetoresistance oscillation in the semiconductor material, GaAs, at low the cryonic temperatures is mainly studied in this thesis. By changing the parameters, such as applied magnetic fields temperatures modulation doped and so on, the magnetoresistance in the2DEG will change its initial oscillatory occurrence in these nonlinear processes, and form a novel magnetoresistance oscillatory occurrence. As a result, we can gain fruitful material electrical properties and electronic subband properties by studying the magneto-transport measurements of MO occurrence in2DEG.The thesis is composed of four themed chapters. Chapter1explains the basic properties of GaAs and fundamental knowledge and concepts in2DEG.Chapter2mainly relates to the principles of cryogenic refrigerator and calibration of the low-temperature thermometer.In chapter3, the preparation method of GaAs devices is presented. Finally, we show the low-temperature experimental transport results collected on3He system and its corresponding discussions.