Full Counting Statistics Of The Serially Two Quantum Dots With Spin-orbit Coupling

Due to experimental adjustability of relevant parameters in the coupled-quantum-dots system, its quantum transport characteristics have become a research focus in the low-dimension quantum system. In particular,the spin-orbit coupling effect can provide an approach to efficiently controlling electron spin under the condition of no external magnetic field. Therefore, the influence of the spin-orbit coupling effect on quantum transport characteristics of the coupled-quantum-dot system has aroused wide research attention.However, researches into how to extract the spin-orbit coupling constants from the coupled-quantum-dot system based on quantum transport characteristics of the current have still been insufficient. On the other hand, it has been experimentally verified that the high-order current cumulant moment can provide more electronic transport mechanism information that average current and differential conductance cannot reveal. Therefore, it is of vital significance to study the dependency of the spin-orbit coupling effect on its current high-order cumulant moment, and to discuss the feasibility of acquiring spin-orbit coupling parameters from the coupled-quantum-dot system based on the current high-order cumulant moment.In this paper, firstly we introduce the serially quantum dots(QDs) model,and based on this model we introduce the particle-number-resolved quantum master equation and full counting statistics. Secondly, discussing the effects of spin orbit coupling, coupling strength between two QDs, tunneling coupling strength, spin polarization, and energy detuning on the FCS,in the situationwhich two QDs at the same level and at the different level.Results has been obtained as follows:(1) It will appear obvious super poisson noisewhen the electron from the single occupied state to the empty occupied state;(2) Spin-orbit coupling has a great impact on the first-third order cumulants, especially for higher-order cumulants when spin polarization is bigger;(3) The first-third order cumulants has an obvious change when the difference between the coupling strength between two QDs and the strength of SO is very small;(4) Spin-orbit coupling has a obvious impact on current shot noise and skewness when the coupling strength between two QDs and the tunneling coupling strength is an order of magnitude;(5) Compared with two QDs at the same level, the effect of spin-orbit coupling to the first-third order is bigger when two QDs' energy detuning;(6) Because the slope between skewness and spin orbit coupling is almost a constant value, we can obtain the strength of spin orbit coupling by the skewness in the experiment.The above research findings can provide a theoretical basis for applications of the coupled-quantum-dot system to the solid-state quantum calculation.