抛物势量子点电荷量子比特的消相干  

The Decoherence of the Parabolic Linear Bound Potential Quantum Dot Charge Qubit

作　　者：孙家奎[1] 李红娟[1] 肖景林[1] 

机构地区：[1]内蒙古民族大学物理与电子信息学院,内蒙古通辽028043

出　　处：《内蒙古民族大学学报（自然科学版）》2009年第3期241-243,共3页Journal of Inner Mongolia Minzu University：Natural Sciences

基　　金：国家自然科学基金资助项目(10747002)

摘　　要：通过求解能量的本征方程得出了抛物线性限制势下柱形量子点中电子的基态、激发态本征波函数及其本征能量,将基态、激发态二能级系统作为一个量子比特,利用费米黄金规则讨论了量子点受限长度对量子点消相干速率的影响,同时讨论了电子在空间概率密度分布的时间演化和振荡周期.数值计算结果表明,量子比特的消相干速率随受限长度的增加而减小,振荡周期随受限长度的增加而增加.电子的概率密度在空间呈周期性的变化.In an unsymmetrical parabolic potential quantum dot（QD）,the eigenenergies of the grornd state and the first-excited state,the eigenfounctions of the ground state and the first-excited state are obtained.This system in QD may be employed as a two-level quantum system—qubit,we obtain the relationship of the decoherence time based on the Fermi Golden Rule,the period of oscillation and longitudinal confined length.The time evolution of the electron density are discussed.It can be seen that the decoherence time and the period of oscillation increases with increasing the longitudinal confined length,the density of electron oscillates with a period in the space.

关 键 词：量子点 电荷量子比特 消相干 

分 类 号：O469[理学—凝聚态物理]