Transport Property Induced By Magnetic Field In Spin-Orbit Coupled Electron System In Quantum Well

With the advancement of the manufacturing process, the size ofsemiconductor devices becomes smaller and smaller, the impact ofquantum effect can not be ignored. On the other hand, a large part of theconsumed energy devices is wasted and the traditional energyprevent-losing method that mainly lowers the operating voltage has beenclose to its limit. Thus, the spintronics came into being with theconsideration of degrees of freedom of electronics spins by combiningwith microelectronics and magnetism. The researches for the spintronicsenable the devices to be miniaturized as far as it can be and exploit muchnewer and richer functionalities.The transport property of the electron spin has become one of the hottopics in spintronics. It has the practical value in quantum computing,quantum information and semiconductor materials. In addition, it hasattracted a wide interest of researchers in recent years due to the unique role of the spin-orbit interaction in the emerging field of semiconductorspintronics. The spin-orbit interaction is a result of quantum effect. Itsessence is the effect of external electric field on the spin. This effectprovides a new way to control the spin by taking advantage of electricfield or gate voltage, which is a feasible way to manipulate spin insemiconductor and to control of spin transport.In this thesis, we studied the electron transport property induced bymagnetic field in spin-orbit coupled electron system in quantum well.With a small amount of impurities, under the influence of appliedtime-dependent magnetic field, considering the spin-orbit coupling andZeeman splitting effect, by using quantum transport equation and densitymatrix method, we calculated the current density, and found that theelectronic current is induced from the time-dependent magnetic field inthis system.The role of the in-plane magnetic field is twofold in the presentsystems. According to our analytical results or the Fermi gold rule, thein-plane magnetic field induces electronic transitions between the spindependent eigenstates. This characteristic of the in-plane magnetic fieldwas also used to generate the spin-polarized current in quantum wireswith the spin-orbit interaction. On the other hand, the in-plane magneticfield provides the effective driving field in our formalism, whichoriginates from the Zeeman coupling and the spin-orbit interaction. The in-plane magnetic field changes the spin direction through Zeemancoupling and further has an influence on the electron momentum throughspin-orbit interaction. In this sense, the in-plane magnetic field has asimilar effect as that of the normal electric field on electronic transport.The dependence of the induced current upon the second order of theimpurity potentials indicates the random impurity is necessary to provideelectron momentum relaxation. As a result, the induced current is due tothe photon-excited electrons scattered by impurities in the presence ofboth the spin-orbit coupling and the in-plane time-dependent magneticfield.According to our calculating results, the current is stronglydependent on the material parameters of the system, such as spin-orbitcoupling, electron density, width of the quantum well, applied magneticfield strength and its frequency. Especially the width of two-dimensionalsemiconductor quantum well makes the current change obviously. If wereduce the width by half one time than before, the current density isincreased by order of its a magnitude. Through our research, provides away to use magnetic regulating charge in spin-orbit coupling system.