双激子和浸润层泄漏以及俄歇俘获对量子点Rabi振荡衰减的影响

研究了脉冲激光激发下半导体量子点激子Rabi振荡中多能级过程引起的退相干特性.运用多能级粒子数运动方程组，分别计算和分析了三种多能级过程(双激子、浸润层泄漏以及俄歇俘获过程)对量子点中Rabi振荡衰减的影响.分析表明，双激子的影响在激发脉冲的脉宽较长时(>5ps)可以忽略；浸润层的泄漏虽然使得激子基态上粒子数振荡的振幅随着激发场的增强而减小，但是同时也导致了振荡平均值的减小；分析和讨论了两种俄歇俘获方式对激子振荡和复合发光的影响. 关键词： Rabi振荡 半导体量子点 退相干 俄歇俘获

The effect of biexciton, wetting layer leakage and Auger capture on Rabi oscillation damping in quantum dots

The decoherence of Rabi oscillation with multi-level processes in semiconductor quantum dots excited by laser pulses is investigated. By using population dynamic equations of multi-level system, the effect of three kinds of multi-level processes on the damping of Rabi oscillation in quantum dots are numerically simulated and discussed. The effect of biexciton can be neglected when the pulse width is larger than 5ps; the population leakage to wetting layer results in the decreasing of the amplitude and average of the population oscillation on the exciton ground state with the increasing of the excitation intensity; the effect of the two kinds of Auger capture processes on the Rabi oscillation and the spectral width of the photoluminescence from the exciton recombination are also discussed.