光学调控非对称双量子点系统的相干布居转移  

Optical Control of Coherent Population Transfer in Asymmetric Double Quantum-Dot System

作　　者：郭裕[1] 刘鹏飞 束传存 Guo Yu;Liu Pengfei;Shu Chuancun(School of Physics and Electronic Science,Hunan Provincial Key Laboratory of Flexible Electronic Materials Genome Engineering,Changsha University of Science and Technology,Changsha 410114,Hunan,China;School of Physics and Electronics,Hunan Provincial Key Laboratory of Nanophotonics and Devices,Hunan Key Laboratory of SuperMicrostructure and Ultrafast Process,Central South University,Changsha 410012,Hunan,China)

机构地区：[1]长沙理工大学物理与电子科学学院,柔性电子材料基因工程湖南省重点实验室,湖南长沙410114 [2]中南大学物理与电子学院,纳米光子学与器件湖南省重点实验室,超微结构与超快过程湖南省重点实验室,湖南长沙410012

出　　处：《光学学报》2022年第23期180-187,共8页Acta Optica Sinica

基　　金：国家自然科学基金(61973317);湖南省自然科学基金(2022JJ30582);湖南省教育厅基金(20A025);长沙市自然科学基金(kq2007001)。

摘　　要：利用Magnus展开方法研究了单个激光脉冲驱动的三能级非对称双量子点系统从基态到间接激子态的相干布居转移。通过对量子系统的时间演化幺正算符进行一阶Magnus展开,解析得到非旋转波近似条件下实现非对称双量子点系统完全布居转移的脉冲面积条件,并通过数值求解含时薛定谔方程进行数值模拟验证。通过比较高斯脉冲、多周期余弦式脉冲和单周期余弦式脉冲等三类不同形状的脉冲在实现布居转移中的效果发现,只要满足脉冲面积条件,不同形状的脉冲都可以实现完全布居转移,从而揭示了布居转移过程中光场振幅的物理意义。对三类脉冲方案的鲁棒性的分析发现,单周期余弦式脉冲在抵抗激光脉冲参数的不稳定性和退相干效应的影响方面要优于高斯脉冲和多周期余弦式脉冲。该研究为实验研究光场精准调控非对称量子点系统的量子态提供了重要理论依据,在量子光学和量子信息科学领域具有重要研究价值。We use the Magnus expansion method to study the problem of coherent population transfer from the ground state to the indirect exciton state in a three-level asymmetric double quantum-dot system driven by a single laser pulse.By the first-order Magnus expansion of the time-evolution unitary operator of the quantum system,we analytically obtain the pulse-area conditions for achieving complete population transfer of the asymmetric double quantum-dot system without rotation wave approximation.Then,we solve the time-dependent Schr?dinger equation of the system for numerical verification of the pulse-area conditions.Furthermore,we compare the performance of the Gaussian pulse,the multiperiod cosine pulse,and the single-period cosine pulse in population transfer.The results show that all three pulses can achieve complete population transfers as long as the pulse-area conditions are satisfied,which reveals the physical significance of optical field amplitude in population transfer.The robustness analysis of the three pulse schemes indicates that the single-period cosine pulse is superior to the other two in the resistance against unstable laser pulse parameters and the decoherence effect.This work offers a vital reference for precise optical field control over the quantum state of asymmetric quantum-dot systems,which is of significant value in quantum optics and quantum information science fields.

关 键 词：量子光学 非对称双量子点 布居转移 激光脉冲 

分 类 号：O431[机械工程—光学工程]