Patton B, Woggon U, Langbein W
Fachbereich Physik, Universität Dortmund, Germany.
Phys Rev Lett. 2005 Dec 31;95(26):266401. doi: 10.1103/PhysRevLett.95.266401. Epub 2005 Dec 21.
We present measurements and simulations of coherent control and readout of the polarization in individual exciton states. The readout is accomplished by transient four-wave mixing detected by heterodyne spectral interferometry. We observe Rabi oscillations in the polarization, which show half the period of the Rabi oscillations in the population. A decrease of the oscillation amplitude with pulse area is observed, which is not accompanied by a change in the dephasing time. This suggests the transfer of the excitation to other states as the origin of the Rabi-oscillation damping. Detuning of the excitation enables the control of the polarization in phase and amplitude and is in qualitative agreement with simulations for a two-level system. Additionally, simultaneous Rabi flopping of several spatially and energetically close exciton states is demonstrated.
我们展示了对单个激子态中极化的相干控制和读出的测量与模拟。读出是通过外差光谱干涉测量法检测的瞬态四波混频来实现的。我们观察到极化中的拉比振荡，其周期是布居数中拉比振荡周期的一半。观察到振荡幅度随脉冲面积减小，且去相位时间没有变化。这表明激发转移到其他态是拉比振荡阻尼的起源。激发的失谐能够控制极化的相位和幅度，并且在定性上与两能级系统的模拟结果一致。此外，还展示了几个空间和能量上相近的激子态的同时拉比翻转。
