串联耦合双量子点的电流有限频率散粒噪声谱:广义哈伯德模型  

Finite-frequency Shot Noise in a Serially Coupled Double Quantum Dot System Described by Generalized Hubbard Model

作　　者：吕星云 郭晓庆 王佳才 吴敏 薛海斌 LU Xingyun;GUO Xiaoqing;WANG Jiacai;WU Min;XUE Haibin(Key Laboratory of Interface Science and Engineering in Advanced Materials,Ministry of Education,Taiyuan University of Technology,Taiyuan 030024,China;College of Physics and Optoelectronics,Taiyuan University of Technology,Taiyuan 030024,China)

机构地区：[1]太原理工大学新材料界面科学与工程教育部重点实验室,山西太原030024 [2]太原理工大学物理与光电工程学院,山西太原030024

出　　处：《山西大学学报（自然科学版）》2023年第6期1358-1369,共12页Journal of Shanxi University(Natural Science Edition)

基　　金：山西省应用基础研究计划项目(20210302123184,201601D011015);山西省高等学校优秀青年学术带头人支持计划(163220120-S)。

摘　　要：利用粒子数分辨的量子主方程方法,研究了耦合串联双量子点系统中广义哈伯德模型预测的三个新的跳跃过程,即占据数调制的跳跃过程、自旋反平行的交换跳跃过程、电子对跳跃过程对其电流有限频率散粒噪声谱的影响。数值计算结果表明,对于两个量子点的能级失谐情形,当电流有限频率散粒噪声谱上的峰、谷数目之和为8个时,可以作为占据数调制的跳跃过程的存在判据;而对于两个量子点的能级共振情形,其峰、谷个数之和为5,6,7和8,分别表示不存在广义哈伯德模型预测的三个新的跳跃过程、仅存在占据数调制的跳跃过程、仅存在自旋反平行的交换跳跃过程和电子对跳跃过程,以及存在广义哈伯德模型预测的三个新的跳跃过程。因此,上述结果提供了一种探测广义哈伯德模型预测的三个新的跳跃过程的理论方案。Using an effective particle number resolved quantum master equation,the influences of the three new hopping processes predicted by the generalized Hubbard model,namely,the electron occupation modulated hopping processes,the electron anti-parallel-spin exchange hopping processes,and the electron-pair hopping processes,on the finite-frequency shot noise in a serially coupled double quantum dot(QD)system are studied.It is demonstrated that the maximum number of the dips and peaks in the cases of the energy-level detuning between the two QDs is 8,which indicates that the coupled QD system has the electron occupation modulated hopping processes.Whereas the maximum number of the corresponding peaks and valleys in the cases of the energy-level alignment between the two QDs are 5,6,7 and 8,which indicate that the coupled QD system does not have the three new hopping processes,has only the electron occupation modulated hopping processes,has only the electron anti-parallel-spin exchange hopping processes and the electron-pair hopping processes,and has the three novel hopping processes,respectively.Therefore,these results provide an alternative way to detect the three new hopping processes predicted by the generalized Hubbard model.

关 键 词：串联耦合双量子点 广义哈伯德模型 有限频率散粒噪声 

分 类 号：O413[理学—理论物理]