Carrier-carrier scattering in photoexcited intrinsic GaAs quantum wells and its effect on femtosecond plasma thermalization.
Carrier-carrier scattering in photoexcited intrinsic GaAs quantum wells and its effect on femtosecond plasma thermalization.
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光激发本征 GaAs 量子阱中的载流子散射及其对飞秒等离子体热化的影响。
DOI：
10.1103/physrevb.51.16860
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发表时间：
1995
期刊：
影响因子：
--
通讯作者：
Cambel
中科院分区：
文献类型：
--
作者：
Mosko;Mošková;Cambel
当通过短激光脉冲在接近本征GaAs量子阱的带边缘处激发非热电子-空穴等离子体时，等离子体热化发生在约200 fs内[Knox等人，物理修订信函56，1191（1986）]。根据先前的Monte Carlo模拟，这种快速过程是由于载流子-载流子（c-c）散射。我们的工作发现，c-c散射导致的热化比观察到的慢得多。这一结论是从修正的c-c散射率的Monte Carlo模拟以及多体库仑动力学的分子动力学模拟中得出的，因此解释快速热化的问题再次出现。我们得到的c-c散射率比以前的模拟小四倍。与体半导体的类似研究相比，我们发现在蒙特卡罗模拟中的热化速度明显快于分子动力学模拟。这种效应归因于蒙特卡罗方法中对二元碰撞的玻恩近似处理的失败。
When a nonthermal electron-hole plasma is excited close to the band edge of the intrinsic GaAs quantum well by a short laser pulse, the plasma thermalization occurs within about 200 fs [Knox et al., Phys. Rev. Lett. 56, 1191 (1986)]. According to previous Monte Carlo simulations, this fast process is due to carrier-carrier (c-c) scattering. Our work finds that c-c scattering causes much slower thermalization than the observed one. This conclusion is drawn from the Monte Carlo simulation with revised c-c scattering rates as well as from the molecular-dynamics simulation of many-body Coulomb kinetics, and the problem of explaining the rapid thermalization thus reappears. The c-c scattering rates derived by us are four times smaller than those used in previous simulations. In contrast to similar studies of bulk semiconductors we find a remarkably faster thermalization in the Monte Carlo simulation than in the molecular-dynamics simulation. The effect is ascribed to the breakdown of the Born-approximation treatment of binary collisions in the Monte Carlo method.