圆柱形GaAs/Al_xGa_(1-x)As量子环中类氢施主杂质态的电场效应

On the Electric Field Effect of Hydrogenic Donor Impurity in the Quantum Ring of Cylindrical GaAs/Al_xGa_(1-x)As

在有效质量近似理论下,利用变分法研究了外电场下圆柱形GaAs/Al_xGa_(1-x)As量子环中类氢施主杂质束缚能。讨论了施主杂质束缚能与量子环尺寸(径向厚度、高度)、杂质位置以及外电场间的变化规律。结果表明:随着量子环径向厚度(高度)的增大,中心施主杂质束缚能先增大后减小,显示有一极大值;施加的电场明显地改变了量子环中电子波函数的分布,导致施主杂质束缚能相应的改变;施主杂质束缚能随杂质位置的变化呈现出规律性。

Within the framework of the effective mass approximation and with the variational me th o d , th e author of this paper have studied the binding energy of the hydrogenic donor im-purity in the quantum ring of cylindrical GaAs/AlxGai-xAs and researched the change rules of the donor impurity binding energy, the size of quantum ring （radial thickness, height ） , impurity position and the external electric field are discussed. The results show th at when the quantum ring radial thickness （height） increases, center donor impurity binding energy increases first and then decreases, with a maximum value at a certain stage, the applied elec-tric field significantly changes the distribution of the electron wave function in the quantum r ing, resulting in change of the donor impurity binding energy, and the donor impurity bind-ing energy changes with the impurity position regularly.