Study On Quantum Dot Electronic Transport Properties By Lindblad Quantum Principal Equation

The mesoscopic system (the quantum dots) is the important physical devices for the future of nanometer quantum circuit, it has been studied long ago,until now, it is a hot problem. The way of study of the transport properties of quantum dots by sloving the Lindblad master equations is developed by Dzhioev in2011based on the Liouville equation. The Liouville equation is suitable for the isolated system, when the system has energy exchange with the outside,it cannot be used. But the Lindblad master equations can be used in this situation, and it not only can be used to the system with not consider the Coulomb interaction of the electrons,but also the system with the Coulomb interaction of the electrons. So the Lindblad master equations is a very good way to study the microcosmic system,and has very high application value.This article mainly study the system composed by three quantum dots by solving the Lindblad master equations. We do not consider the Coulomb interaction between electrons, and the system can be fall into horizontal alignment and vertical alignment. The two arrangement have the same coupled between the quantum dots, also the coupled between the quantum dots and the electrodes. Two models difference lies in the electrodes coupled different quantum dots. In the horizontal alignment model, the left electrodes coupled with the first dot and the right electrodes coupled with the third dot. But in the vertical arrgement model the electrodes only coupled with the second dot. We calculate the current and number of electrons occupying in each energy level of the system along with the change of left and right electrodes’chemical-potential difference. Aslo we calculate the number of electrons occupying on each dot. We can get that the energy level of the system have important influence on the current and the number of electrons occupying.We further studies the current and the number of electrons occupying of the system along with the change of gate voltage. And we compared the result of the two modes. We find that the energy of a quantum dot has important influence on the transport properties.In addition to the not consider the electronic Coulomb interaction between three quantum dot system, we also studied the three dots syetem with coulomb interaction between electrons, In the same way, we falled the quantum dots system into horizontal alignment and vertical alignment of two models. We also calculated the current and the number of electrons occupying of the system along with the change of left and right electrodes’chemical-potential difference or gate voltage. Due to taking into account the coulomb interaction of the electrons, the three quantum dots system will be divided into six enery level because the coulomb interaction. The electron transport is relatively complex, and we have get some conclusions. We expect that this article will be useful people to making the similar structure components in the laboratory.