Theoretical Study On Electronic Transport Properties Of Coupled-Quantum-Dot System Connectted To Four Terminals

With further investigation of properties of quantum dots, the people gradually take note of coupled-quantum-dots system. The future miniaturization of electronic devices has directed attention to the study of discrete structures. Such as, more and more people have recently begun to notice the investigation of the electronic transport properties about quantum dot wires. On the basis of this, we theoretically investigate the electronic transport properties of several kinds of new coupled-quantum-dot-wires systems by using the non-equilibrium Green's function technique. The characteristic of the quantum dot system is obtained, which will offer theoretic foundation for future nanoelectronics'design.We first investigate that the electronic transport properties of a system of two quantum-dot wires coupled to each other via tunneling coupling between the middle dots in each wires, connected to four electron reservoirs. For simplicity of numerical calculation, we assume that each quantum-dot wires consist of three quantum dots. We have obtained the current formula of the system through the use of Dyson equations and equations of motion method for Green functions. In numerically analysis, we investigate the variety of transmission probability T (ω) as a function of electron energyωwhen the tunnel coupling amplitude between two quantum-dot wires or single-dot energy levels change. In addition, we present the differential conductance as a function of the chemical potential of the input terminal at various temperatures.We finally investigate that the electronic transport properties of quantum dot wires system in which there are two branches. For this system, we choose a simple model to systemically study. We find that equivalent-branch influence electronic transport of our system. We carry out the contrast among the system...