DC-AC驱动下耦合双量子点分子中激子的动力学行为  

Dynamic Behavior of Excitons in Coupled Double Quantum Dots Driven by DC-AC Electric Fields

作　　者：苏希玉[1] 全秀梅[1] 郭德军[1] 

机构地区：[1]曲阜师范大学物理工程学院,曲阜273165

出　　处：《Journal of Semiconductors》2007年第3期404-409,共6页半导体学报（英文版）

摘　　要：利用两点Hubburd模型和Floquet理论,用数值方法求解了含时Schdinger方程,给出了电子-空穴局域于初始态的几率在20个驱动周期内的最小值,研究了在直流和交流电场驱动下耦合双量子点分子中激子的动力学行为.结果表明,在弱场情况下,激子主要在局域态之间隧穿;在强场情况下,电子和空穴可以独立地在量子点间隧穿.驱动场倾向于使电子和空穴在空间分离,但在合适的条件下量子点中的电子和空穴在短时间内仍可以保持在初始局域态.直流电压破坏系统的动力学对称性,并对动态局域化产生影响.With a two-site Hubbard model and the Floquet theory,the dynamic behavior of excitons in coupled double quantum dots driven by DC-AC electric fields is investigated. The time-dependent Schrodinger equation is numerically solved,and Pmin, the minimum probability for the electron and the hole to remain in the initial localized state within 20 periods of the external field,is given. Results show that for a weak field,the exciton mainly oscillates between two localized states; however, for a strong field,the electron and the hole can independently tunnel between the two quantum dots. The driving field tends to drive the electron and the hole apart,and under appropriate conditions they can be localized in the initial state for a short time. The DC field breaks the dynamic symmetry of the system and affects the dynamic localization.

关 键 词：FLOQUET理论 准能 局域态 动态局域化 

分 类 号：O431.2[机械工程—光学工程]