激子自旋弛豫对简并量子点发射光子对纠缠度的影响  

The influence of spin relaxation on the entanglement of photon pairs emitted from degenerate exciton quantum dot system

作　　者：刘绍鼎[1] 程木田[1] 王霞[1] 王取泉[1] 

机构地区：[1]武汉大学物理系,武汉430072

出　　处：《物理学报》2007年第8期4924-4929,共6页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:10534030;10474075)资助的课题.~~

摘　　要：利用粒子数运动方程和量子回归理论,计算了单个半导体量子点双激子体系脉冲激发下粒子在各能级间辐射跃迁的二阶交叉相关函数以及系统发射光子对的偏振密度矩阵.分析了激子态能级简并量子点体系发射光子对偏振纠缠特性,讨论了纠缠度随激子态间自旋弛豫的变化关系.研究表明,激子自旋弛豫会破坏该系统发射光子对的纠缠度.The second-order cross correlation function of the photon emission and the polarization density matrix of the photon pairs emitted from the biexciton system of single semiconductor quantum dots under pulsed excitation were calculated using the dynamical population density matrix equations and quantum regression theorem. The entanglement of the photon pairs emitted from the single quantum dot with degenerate exciton states were investigated, and the relationship between the entanglement and the spin relaxation rate was also discussed. The simulations revealed that the spin relaxation destroys the entanglement of the photon pairs emitted from this system.

关 键 词：纠缠光子对 半导体量子点 二阶相关函数 

分 类 号：O471.3[理学—半导体物理]