半导体量子结构中量子力学新效应

NOVEL QUANTUM-MECHANIC EFFECTS IN SEMICONDUCTOR QUANTUM STRUCTURES

量子力学波函数的相位、相干性与退相干 ,正成为当前物理学研究的一个热点 .半导体材料及其低维量子结构 ,以其制备工艺的精良和物理研究的透彻而成为最佳研究对象 .对于半导体量子结构中载流子相位和关联的实验研究 ,主要遵循两条路线 :(1)使系统特征尺度与相干长度可比 ,研究介观系统与小量子系统输运过程中量子相干效应 ;(2 )发展超短脉宽激光器与超快探测技术 ,研究与相干时间可比的时间尺度内的动力学 .文章结合笔者的研究工作 ,着重介绍半导体及其量子结构中超快光学过程研究 ,包括电声子散射的量子动力学 ,直流与THz交流电场驱动的半导体超晶格激子态、吸收光谱与四波混频谱 ,动力学Fano共振和多体相互作用中超越平均场近似的重要性 .

The phase, coherence and decoherence of quantum states have been a focus of research since the 1980s′. Almost perfect in structure and extensively studied, semiconductor quantum structures are ideal systems for studying such phenomena in modern physics. In mesoscopic physics where the coherence length is comparable with the characteristic length of systems, recent experimental advances in ultrafast laser techniques allow us to study phase coherence and dephasing as well as quantum interference in the ultrafast optical processes of semiconductors. Recent advances in this area will be reviewed with emphasis on the authors′ own work, including electron phonon quantum dynamics, Floquet exciton states in dc-and THz ac driven semiconductor superlattices, dynamic Fano resonance, and the treatment of many particle correlations beyond the mean field approximation.