标题： 激子在量子阱结构中空间输运的蒙特卡罗模拟 显示英文标题

标题： Monte Carlo Simulations of the Spatial Transport of Excitons in a Quantum Well Structure

摘要： 蒙特卡罗模拟了量子阱结构中激子的空间输运 Yutaka Takahashi (电气与信息工程系，山形大学) 通过系综蒙特卡罗方法模拟了GaAs量子阱结构中非平衡激子的平面内空间输运。 模拟考虑了残留重空穴、粒子间库仑散射、LA声子散射以及激子/载流子界面粗糙度散射。 发现与载流子-载流子散射显著的自由电子/空穴系统相反，由于激子-载流子和激子-激子散射的相对较小的散射率，界面粗糙度散射是激子的主要过程。 这对激子的空间运动和能量弛豫都有很大影响。 在几个激子温度和界面粗糙度参数下，模拟了激子的空间和动量分布，持续时间达500 ps。 我们发现激子输运可以被视为一种扩散运动，其扩散系数随时间变化。 扩散性变化是因为激子的平均速度通过激子与残留重空穴/晶格系统的能量传递而变化。 显示英文摘要

摘要： Monte Carlo Simulations of the Spatial Transport of Excitons in a Quantum Well Structure Yutaka Takahashi (Dep. of Electrical and Information Eng., Yamagata University) The in-plane spatial transport of nonequilibrium excitons in a GaAs quantum well structure has been simulated with the ensemble Monte Carlo method. The simulation has been performed for excitons in the presence of residual heavy holes including the interparticle Coulomb scatterings, LA phonon scatterings, and exciton/carrier-interface roughness scatterings. It has been found that, in contrast to the free electrons/holes system in which the carrier-carrier scattering is significant, the interface roughness scattering is the dominant process for excitons because of the relatively small scattering rate of exciton-carrier and exciton-exciton scatterings. This strongly affects both the spatial motion and the energy relaxation of excitons. The spatial and momentum distributions of excitons have been simulated up to 500 ps at several exciton temperatures and interface roughness parameters. We have found that the exciton transport can be regarded as a diffusive motion whose diffusion coefficient varies with time. The diffusivity varies because the average velocity of excitons change through the energy transfer between the excitons and the residual heavy hole/lattice system.