Dark states and Aharonov-Bohm oscillations in multi-quantum-dot systems  

作　　者：王琼 刘军 唐宁 曾浩生 

机构地区：[1]Key Laboratory of Low-Dimensional Quantum Structures and Quantum Control of Ministry of Education,and Department of Physics,Hunan Normal University

出　　处：《Chinese Physics B》2011年第2期30-35,共6页中国物理B（英文版）

基　　金：supported by the National Basic Research Program of China (Grant No. 2007CB925204);the National Natural Science Foundation of China (Grant No. 10775048);the Key Project of the Chinese Ministry of Education (Grant No. 206103);the Construct Program of the National Key Discipline

摘　　要：We study the formation of dark states and the Aharonov-Bohm effect in symmetrically/asymmetrically coupled three- and four-quantum-dot systems. It is found that without a transverse magnetic field, destructive interference can trap an electron in a dark state. However, the introduction of a transverse magnetic field can disrupt the dark state, giving rise to oscillation in current. For symmetrically structured quantum-dot systems, the oscillation has a period of one flux quanta. But for asymmetrically structured dot systems, the period of oscillation is halved. In addition, the dephasing due to charge noise also blocks the formation of dark states, while it does not change the period of oscillation.We study the formation of dark states and the Aharonov-Bohm effect in symmetrically/asymmetrically coupled three- and four-quantum-dot systems. It is found that without a transverse magnetic field, destructive interference can trap an electron in a dark state. However, the introduction of a transverse magnetic field can disrupt the dark state, giving rise to oscillation in current. For symmetrically structured quantum-dot systems, the oscillation has a period of one flux quanta. But for asymmetrically structured dot systems, the period of oscillation is halved. In addition, the dephasing due to charge noise also blocks the formation of dark states, while it does not change the period of oscillation.

关 键 词：quantum dot dark state Aharonov Bohm effect 

分 类 号：O413.1[理学—理论物理]