半导体量子阱中弱耦合磁极化子的性质

采用线性组合算符和改进的LLP变分法,研究了在考虑电子自旋情况下无限深量子阱中弱耦合磁极化子的性质。导出了弱耦合磁极化子的声子平均数、基态能量和电子自旋能量与磁极化子基态能量之比的绝对值的表达式。并对两种不同阱材料的量子阱进行了数值计算,结果表明:磁极化子的声子平均数随电子-LO声子耦合常数和阱宽的增加而增大,并且最终随着阱宽的增加而趋于体情况下的极限值;由于电子自旋能的作用使磁极化子的基态能量由不考虑电子自旋下的一条分裂为两条,并且它随阱宽和电子-LO声子耦合常数的增加而减小,随回旋共振频率(磁场)的增加而增大。电子自旋作用能否忽略由回旋共振频率和阱材料本身的性质决定。

Properties of the Weak-coupling Magnetopolaron in a Semiconductor Quantum Well

The properties of the weak-coupling magnetopolaron in semiconductor quantum well were studied by using the linear combination operator and a modified LLP variational method considering the electron spin. The mean number of phonons, the ground state energy of the weak-coupling magnetopolaron and the ratio(absolute value) of the electron spin energy to the ground state energy in an infinite quantum well were derived. Numerical results show that the mean number of phonons increases with enhancing the electron-LO-phonon coupling constant and the well width, and at last approaches to the limiting value of the bulk case; the ground state energy of the magnetopolaron becomes two branches from one branch due to the influence of the electron spin, which decreases with increasing the well width and electron-LO-phonon coupling constant, and it also increases with increasing the cyclotron resonance frequency.It depends on the cyclotron resonance frequency and the properties of the well material whether the effect of the electron spin energy in the quantum well can be neglected.