非对称方势阱中的激子及其与声子的相互作用  

Excitons and effects of phonons on excitons in asymmetric square quantum well

作　　者：邓艳平[1] 吕彬彬[1] 田强[1] 

机构地区：[1]北京师范大学物理系,北京100875

出　　处：《物理学报》2010年第7期4961-4966,共6页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:10574011)资助的课题~~

摘　　要：采用类LLP(Lee-Low-Pines)变换和分数维变分法,在讨论有限深非对称方势阱Ga1-xAlxAs/GaAs/Ga0.7Al0.3As的分数维基础上,计算了其中激子的基态能量以及声子对其影响,随着势阱宽度增加,激子能量先减小后增大,出现一个最小值.讨论了一侧势垒高度变化对分数维、激子基态能量的影响,并发现声子作用使得激子能量明显增大.另外,非对称方势阱中的激子结合能随阱宽的减小而增大,而且随一侧势垒的增大而增大.By LLP（Lee-Low-Pines）-like transformation and fractional-dimension variational treatment,the ground-state energies of excitons confined in Ga1-xAlxAs /GaAs /Ga0.7Al0.3As asymmetric square quantum well and the influence of phonons are demonstrated.The exciton ground-state energy has a minimum value with the increasing well width.And we make clear the effects of the barrier height on the fractional dimension,exciton ground energy and binding energy.After taking into account of the interaction of exciton with LO-phonons,the values of the exciton ground-state energies increase remarkablely.Moreover,the exciton binding energy increases as the asymmetric well-width decreases or the barrier height increases.

关 键 词：非对称方势阱 激子 声子 基态能量 

分 类 号：O471.5[理学—半导体物理]