Effects of resonant coupling on terahertz-range coherent phenomena in semiconductor superlattices

利用飞秒泵浦-探测技术研究了共振波函数耦合对半导体量子阱结构中相干振荡、激子量子拍频和Bloch振荡动力学性质的影响。共振耦合，这导致相关的过渡能的反交叉行为，清楚地检测到电反射光谱作为电场强度的函数。研究发现，在共振耦合条件下，相干振荡的频率和强度发生显着变化。实验结果合理地解释了电场强度的依赖性的能量和从电反射光谱观察到的光学跃迁的跃迁几率。

Effects of resonant wave-function coupling on dynamical properties of coherent oscillations, excitonic quantum beat and Bloch oscillation, in semiconductor quantum-well structures have been studied with the use of a femtosecond pump-probe technique. The resonant couplings, which cause anticrossing behaviors of relevant transition energies, were clearly detected by electroreflectance spectroscopy as a function of electric field strength. It is found that the frequency and intensity of the coherent oscillation change significantly under the resonant coupling conditions. The experimental results are reasonably explained by the electric-field-strength dependence of the energies and transition probabilities of the optical transitions observed from the electroreflectance spectra.