【作者】 张琪；

【导师】 朱红波；

【作者基本信息】 东北师范大学 ， 理论物理， 2021， 硕士

【摘要】 量子阱体系的量子化分立能级决定了量子阱结构的光电性质,因此也对由该结构制备的器件的性质起着重要作用。由于量子阱结构对放入其中的电子会起到量子限制作用,并且实验上制备和调控量子阱系统的技术已经能够实现,因此量子阱材料被广泛应用于激光电子器件的设计与结构中。电子-低维量子阱体系的自旋轨道耦合会引起的能级的分裂现象。基于不同的结构对称性,主要有Rashba和Dresselhaus两种自旋轨道耦合模式。这样的相互作用导致的Rabi劈裂是典型的场的量子化效应。实验证明窄禁带半导体材料中,Rashba自旋轨道耦合起主要作用,因此在半导体自旋电子学的研究和应用中备受关注。本文研究的是一个电子放在二维量子阱中的系统。为了从动力学上研究此量子阱系统中电子的自旋轨道耦合效应,可以类比量子光学当中腔场和原子之间的耦合,采用J-C模型来描述其基本动力学原理,并且利用慢变近似法,用主方程来求解密度矩阵。由于量子阱系统自旋轨道耦合强度的旋波项和非旋波项可以分别调控,我们就可以单独分析自旋轨道间的非旋耦合和外加经典场的非旋驱动对于在只考虑Rashba自旋轨道耦合时的Rabi劈裂效应的影响。研究表明,腔场和原子的频率共振时,经典场驱动中的非旋波项在原子和腔场强耦合时不可以忽略,也就是说旋转波近似不成立;而在腔场和原子的频率失谐时,经典场的非旋驱动会对左右其中一个峰的宽度和高度产生影响,而对另一个峰不起作用,相应的辐射能谱不再是对称的双线结构。无论在共振还是失谐的情况下,自旋轨道耦合中的非旋波项可以造成Rabi劈裂峰的次劈裂,同时出现高度变矮等非谐演化。在原子与腔场频率失谐时,经典场的非旋波驱动项在正失谐和负失谐两种情况下,Rabi劈裂互为镜像;而自旋轨道间的非旋耦合与经典场的非旋驱动同时存在时,在正失谐和负失谐两种情况下的能级劈裂不再互为镜像。也就是说调制经典光场的驱动可以出现正负失谐Rabi劈裂的镜像行为的产生和消失。更多还原

【Abstract】 The characteristic of quantized energy levels of the system quantum wells determines the photoelectrical properties,and then the dynamics of the related devices.The preparation and modulation about the quantum well system have been realized based on the restrictions on electrons placed in the system.The material of quantum well can be widely used on the design and construction of photoelectrical devices.The spin-orbital coupling of the electron can result in the spliting of the levels.The two typical spin-orbital couplings which are brought about by different symmetrical properties of the semiconductor material,Rashba and Dresselhaus couplings can lead to the spliting of the excited levels,which is the typical quantum effects.In the wide band gap semi-conductor,Rashba coupling performs the main performance,which is attractive to the related study.We study the system of an electron placed in a 2-dimentional quantum well.Such a interaction can be analogue to the cavity-atom interacting system in quantum optics.We adopt the JC model to discuss the dynamics of the electron-quantum well system.The density matrices can be obtained by using the slow-change approximation.Based on the advantage that the rotating wave approximation(RWA)items and the non-rotating wave approximation(NRWA)can be modulated separately,we discuss the effective of the RWA and NRWA on the level spliting.It is same for a classical field driving.The study is focused on the Rashba spin-orbital coupling.The analysis shows that the NRWA interaction of the classical field driving can not be neglected for the condition of resonance between the cavity mode and atomic levels.As the detuning exists,the NRWA interaction of the classical field could only affect the width and height of one of the two peaks.And then the spectrum will not be double any more.The spin-orbital coupling will lead to the sub-spliting of the peaks no matter whether there is the resonance or not,as well the height will change.For the case of detuning,the NRWA of the classical driving can brought about the mirror symmetrical behavior of the splitting for the two conditions of plus and minus detuning.That is not the same for the case that the two kinds of NRWA exist at the same time.Obviously,that is the classical field which eliminate the behavior of mirroring.更多还原