摘要:
讨论了负电荷激子X~-的能-光谱及其Aharonov-Bhom振荡.负电荷激子是三个带电粒子组成的体系,其基函数(基矢)数目大,数值计算艰巨.以往人们常把体系的空间波函数分离成质心运动和相对运动两部分来处理,这种方法误差大,只适用于外加磁场很小的情况.直接由体系的Hamilton量出发,基于角动量守恒,把基矢按总角动量分类.据此提出了一种简便的求解体系的本征矢和本征函数方案,使用该方法使计算时间节省了90%以上.所得计算结果没有抗磁现象,且计算结果与现有的实验数据符合很好.还讨论了环的半径、介质电容率和空穴的有效质量与ABO的关系.
Abstract:
In this paper, the energy-optical spectra and their Aharonov-Bohm oscillation of the negatively charged exciton are studied. A negatively charged exciton is composed of three charge particles, electrons and hole, the number of basic wave functions (basic vectors) which compose the state wave functions are large, so the numerical computing work is quite tedious. So far, many authors usually separate the spatial wave function into motion of mass centre and relative motion parts to save the numerical computing time. There is considerable discrepancy in the results of this method. It only suits the case when the external magnetic field is very weak. Considering the conservation of angular momentum, in case that there is no external electric field, we classify the whole set of basic vectors according to the values of their total orbital angular momentum. Then starting from Hamiltonian directly, we propose an alternative computing method to find the eigen values and eigen functions of the system. Our method can save more than 90% of computer time. There is no so called diamagnetic shift in our results. Our results fit well with the experimental data. The effects of the radii of the quantum ring, the value of dielectric constant and the effective mass of hole on the energy-optics spectra are systematically discussed.