Coupled bloch-phonon oscillations in semiconductor superlattices
Coupled bloch-phonon oscillations in semiconductor superlattices
复制标题
半导体超晶格中的耦合布洛赫声子振荡
DOI：
10.1103/physrevlett.85.1080
复制
发表时间：
2000
影响因子：
8.6
通讯作者：
Ploog
中科院分区：
文献类型：
--
作者：
Dekorsy;Bartels;Kurz;Kohler;Hey;Ploog
我们研究了电子小带宽度大于光声子能量的GaAs/AlxGa1-xAs超晶格中的相干Bloch振荡。在这些超晶格中，布洛赫频率可以调谐成与光学声子的共振。在接近共振的情况下，观察到布洛赫振荡与低声子的直接耦合，从而产生低声子的相干激发。通过布洛赫振荡驱动相干LO声子所需的密度比在块体GaAs中驱动相干LO声子所需的密度小2个数量级。这一现象的理论描述证实了实验结果Ghosh等人，物理学。[j].科学通报，2005(5)。
We investigate coherent Bloch oscillations in GaAs/AlxGa1-xAs superlattices with electronic miniband widths larger than the optical phonon energy. In these superlattices the Bloch frequency can be tuned into resonance with the optical phonon. Close to resonance a direct coupling of Bloch oscillations to LO phonons is observed which gives rise to the coherent excitation of LO phonons. The density necessary for driving coherent LO phonons via Bloch oscillations is about 2 orders of magnitude smaller than the density necessary to drive coherent LO phonons in bulk GaAs. The experimental observations are confirmed by the theoretical description of this phenomenon [A.W. Ghosh et al., Phys. Rev. Lett. 85, 1084 (2000)].