Langbein Wolfgang, Patton Brian
School of Physics and Astronomy, Cardiff University, Cardiff CF24 3AA, UK.
J Phys Condens Matter. 2007 Jul 25;19(29):295203. doi: 10.1088/0953-8984/19/29/295203. Epub 2007 Jun 11.
We review our recent advances in four-wave mixing spectroscopy of single semiconductor quantum dots using heterodyne spectral interferometry, a novel implementation of transient nonlinear spectroscopy allowing the study of the transient nonlinear polarization emitted from individual electronic transitions in both amplitude and phase. We present experiments on individual excitonic transitions localized in monolayer islands of GaAs/AlAs quantum wells and in self-assembled CdTe/ZnTe quantum dots. We investigate the formation of the photon echo from individual transitions, both with increasing number of transitions in the ensemble, and in the presence of temporal jitter of the energy of a single transition. The detection of amplitude and phase of the signal allows the implementation of a two-dimensional femtosecond spectroscopy, in which mutual coherent coupling of single quantum dot states can observed and quantified.
我们回顾了利用外差光谱干涉术对单个半导体量子点进行四波混频光谱研究的最新进展，这是一种瞬态非线性光谱学的新方法，能够对单个电子跃迁发射的瞬态非线性极化的幅度和相位进行研究。我们展示了在GaAs/AlAs量子阱单层岛以及自组装CdTe/ZnTe量子点中单个激子跃迁的实验。我们研究了单个跃迁形成光子回波的情况，包括随着系综中跃迁数量的增加以及单个跃迁能量存在时间抖动时的情况。信号幅度和相位的检测使得二维飞秒光谱学得以实现，其中可以观察和量化单个量子点态之间的相互相干耦合。
