量子点输运系统中电子的等待时间分布  

Electron Waiting Time Distribution in Quantum Dot Transport System

作　　者：王敏 张超[1] 聂一行[1] WANG Min;ZHANG Chao;NIE Yihang(Institute of Theoretical Physics,Shanxi University,Tai yuan 030006,China)

机构地区：[1]山西大学理论物理研究所,山西太原030006

出　　处：《山西大学学报（自然科学版）》2018年第4期727-733,共7页Journal of Shanxi University(Natural Science Edition)

基　　金：国家自然科学基金(11274208)

摘　　要：基于散射理论和紧束缚模型研究了单能级量子点连接两个导线时电子的等待时间分布,讨论了偏压、通道数、温度对等待时间分布的影响。当量子点能级与电极费米面对齐时,等待时间分布不依赖于偏压。当量子点能级偏离了费米面时,分布函数的峰值随着偏压增加而增加,等待时间分布向短时方向移动。对于双通道量子点系统,零等待时间时等待时间分布不为零,而且随着量子点能级偏离费米面,零等待时间时等待时间分布概率降低。随着左导线所加温度降低等待时间分布的极大值向长时间方向移动,而且最大分布概率略有降低,但温度的影响主要是在最大分布概率附近,对长时概率分布影响较小。Based on the scattering theory and the tight-binding model, we study the electron waiting time distribution in a single-level quantum dot coupled two leads. The effects of bias voltage, channel numbers and temperature on the waiting time distribution are discussed. When the quantum dot level is aligned with the Fermi surface of the electrode, the waiting time distribution is independent of the bias voltage. When the quantum dot level deviates from the Fermi surface, the peak of the distribution function increases with the bias voltage increasing, and the waiting time distribution shifts toward shorter time. For a two-channel quantum dot system, the zero-time waiting time distribution is no longer zero and decreases as the quantum dot energy level deviates from the Fermi sea. With the temperature of the left wire decreasing, the maxi- mum value of waiting time distribution moves to a long time and the maximum of distribution decreases slightly. However, the influence of temperature is mainly in the vicinity of the maximum distribution orobability and has little effect on the long-time probability distribution.

关 键 词：量子点 等待时间分布 散射理论 

分 类 号：O488[理学—固体物理] TB383[理学—物理]