摘要
基于Lee-Low-Pines幺正变换,采用Pekar型变分法研究了计及厚度下量子点中强耦合极化子的基态和第一激发态能量本征值和本征函数,在此基础上,以极化子的二能级结构为载体构造了量子点量子比特。数值结果表明:量子比特的概率密度Ψ(ρ,z,t)2分别随磁场的回旋频率ωc、电声子耦合强度α以及量子盘厚度L的增加而减小;概率密度Ψ(ρ,z,t)2随量子盘有效半径R0的增加而增大并呈现近似"Γ型"曲线;概率密度Ψ(ρ,z,t)2随电子横向坐标ρ的变化呈现"正态分布",其形状受到量子盘有效半径R0或厚度L的影响显著;Ψ(ρ,z,t)2随纵向坐标z、时间t和角坐标φ作周期性振荡变化。
Based on the Lee-Low-Pines unitary transformation, the electromagnetic fields dependence of the energies eigenvalues and eigenfunctions of the ground state and the first-excited state of the polaron strongly coupled to the LO-phonon in a quantum dot with the thickness were studied by using the variational method of Pekar type. A quantum dot qubit was constructed based on the two-level polaron. The numerical results represents that the probability density ｜ψ（p,z,t） ｜2 of electron in quantum disks qubit decreases with the increase of the resonant frequency of the magnetic field ωc , the electron-phonons coupling strength a and the thickness of the quantum disk L , respectively. ｜ ψ（p,z,t） ｜2 increases with the increase of the effective radius of the quantum disk R0 and expresses as a ＂F-type＂ curve. The variation of ｜ ψ（p,z,t） ｜2 with ρ is normal distribution, and its shape is significantly affected by the thicknessLand the effective radius R0 of the quantum disk. ｜ψ（p,z,t）｜2 oscillates periodically with the longitudinal positionz , time t and angle coordinate φ2, respectively.
出处
《固体电子学研究与进展》
CAS
CSCD
北大核心
2017年第1期10-14,25,共6页
Research & Progress of SSE
基金
河北省自然科学基金资助项目(E2013407119)
半导体超晶格国家重点实验室开放研究基金资助项目(CHJG200701)
河北科技师范学院科学研究基金资助项目(1301-2506)
关键词
量子点的厚度
极化子
量子比特
电磁场依赖性
quantum dot thickness
polaron
qubit
electromagnetic fields dependence
作者简介
尹洪武（YIN Hongwu）男，1963年生，副教授，辽宁省营口人，目前主要从事低维纳米结构物理性质的研究。
联系作者：E-mail：eerdunchaolu@163．com
