Electron Properties Of The Dot Ring Embedded In The AB Interferometer Driven By Spin Bias

We know the structure of the quantum dot is a quasi zero dimension, its quantum effects have been in-depth study, such as the quantum tunneling effect and coulomb blockage effect, Kondo effect and Fano effect, etc. we found that when the quantum dots coupling with each other, the electronic transport properties will be more complex. If establish coupling relationship between the electrodes and the quantum dots. Then with the nonequilibrium Green’s function method to study the transport properties of the electron through the system, we will find that the process of the electron transport has a lot of physical phenomena, and their transport properties depends on the geometric structure of the quantum dot array and the coupling way with electrode. These electrical properties have potentially devices application value; they can provide theoretical support for designing nanometer electronic switch.In the nanostructure, manipulation of electron spin can realize its application in the field of quantum computing and quantum information. Using the spin control the behavior of the semiconductor has many advantages, thus the spin manipulation has become a widespread research topic. The electron spin in quantum dot (QD) is a natural candidate for the qubit, therefore QD has been regarded as an elementary cell of such a field, and much attention has been paid to the manipulation of the electron spin in QD for its application.In this thesis we have investigated the charge and spin properties in a three-terminal triple-QD ring, by considering the source of spin bias. In quantum dot structures, each of the quantum dots can be coupled with the other. Quantum dot structure determines the electronic transport, So here we’re talking about the electronic transport properties in three quantum dots ring structure driven by spin bias, this kind of structure includes quantum coherence mechanism, Fano effect, for example, AB effect. In addition, local magnetic flux can change the certificate level and electronic number. We anticipate that the spin bias and quantum interference will lead to interesting results. Furthermore, the quantum ring with three or four QDs is feasible to fabricate by virtue of the current nonsocial and mesoscale technology. So it is valuable to study the electronic transport properties in quantum dots ring structure driven by spin bias. It shows that the spin bias drives distinct charge and spin currents in the two drains, dependent on the quantum interference in this structure. And the spin bias also induces the apparent spin accumulation in respective QDs, which help us further clarify the spin motion results. Moreover, we see that the level characteristic of the QD coupled to the source terminal influence the electron transport distinctly.In addition, the spin accumulation in respective QDs was shown. We found that they help us further clarify the spin properties induced by spin bias, especially in the case of finite electron interaction. Moreover, it was observed that the level characteristic of the QD coupled to the source terminal influences the electron transport in a substantial way. When the many-body effect is taken into account within the second-order approximation, it plays a unique role in modifying the charge and spin transport through this structure. In short, with the interlay between spin bias and the relevant parameters, the spin manipulation in this system is theoretically realizable.