外加磁场下抛物型量子线中的带电激子

在一维等效模型下采用有效差分法对抛物型量子阱线中带电激子的束缚能进行了计算,分析了约束势以及磁场对带电激子束缚能的影响,并对带正电激子(X⁺)和带负电激子(X^-)的情况进行了比较.结果表明:电子和空穴的振子强度对带电激子的稳定性有重要影响,X⁺的束缚能不总是比X^-的大,随着空穴振子强度的增加束缚能的函数曲线将会出现交叉,这同实验得到的结果符合;磁场的存在会增加粒子间的束缚,并且磁场对束缚能的影响同振子强度大小有关.关键词：带电激子量子线束缚能磁场

Charged excitons in parabolic quantum-well wires under magnetic filed

The binding energies of the charged excitons(negative X^- and positive X⁺ excitons) are calculated using the finite-difference method within the quasi-one-dimensional effective potential model. The effects due to the magnetic filed and quantum confinements on the binding energy are analyzed, and the following results are obtained:(1) relative electron and hole harmonic oscillator confinement each have a strong effect on the stablity of charged excitons, the binding energy of X⁺ is not always larger than that of X^-, e.g., due to the increase of the hole harmonic oscillator length, leading to the crossing of X⁺ and X^- lines as recently observed experimentally;(2) the magnetic field leads to an increase of the binding energy, and the magnetic field dependence of the binding energy is related to the harmonic oscillator length.