ABSTRACT

We investigated comparatively the electronic and optical properties of GaAs/GaAlAs pseudo-elliptic quantum rings with donor impurity under magnetic field in the absence and the presence of electron spin, taken into account through Rashba and Dresselhaus spin–orbit couplings and Zeeman effect. The energy and absorption spectra were computed for four representative positions of the donor impurity (edges and x(y)-middle of the ring). Both approaches demonstrate the important role played by the impurity position, with the strongest effects corresponding to the impurity placed in the middle of the ring. In the spin absence, the impurity position influences both the energies of the absorption peaks and their oscillatory behaviours in energy and amplitude. In the presence of electron spin, the absorption spectra of the pseudo-elliptic quantum ring become more complex at large magnetic fields as the number of transitions is increased by the splitting of the energy levels and present new distinct features at low and high energies that could be observed experimentally.

摘要

我们通过 Rashba 和 Dresselhaus 自旋轨道耦合和塞曼效应，在没有和存在电子自旋的情况下，比较研究了在磁场下具有施主杂质的 GaAs/GaAlAs 伪椭圆量子环的电子和光学性质。对供体杂质的四个代表性位置（边缘和x(y)-环的中间）。两种方法都证明了杂质位置所起的重要作用，其中最强的影响对应于放置在环中间的杂质。在没有自旋的情况下，杂质位置影响吸收峰的能量及其能量和振幅的振荡行为。在存在电子自旋的情况下，伪椭圆量子环的吸收光谱在大磁场下变得更加复杂，因为能级分裂导致跃迁次数增加，并在低能和高能下呈现出新的独特特征可以通过实验观察。