All-optical generation of coherent in-plane charge oscillations in GaAs quantum wells
All-optical generation of coherent in-plane charge oscillations in GaAs quantum wells
复制标题
GaAs 量子阱中相干面内电荷振荡的全光产生
DOI：
10.1103/physrevb.83.121307
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发表时间：
2011
影响因子：
3.7
通讯作者：
M. Bieler
中科院分区：
文献类型：
--
作者：
S. Priyadarshi;K. Pierz;U. Siegner;P. Dawson;M. Bieler
我们利用相干光激发重空穴和轻空穴激子跃迁的方法，在未掺杂的（110）取向GaAs量子阱中诱导了超快电荷振荡。振荡产生于重空穴态和轻空穴态之间的面内电荷位移，这是由Bloch波函数的周期部分和（110）取向引起的。这些观测结果证明了在平面内波矢的重空穴和轻空穴子带之间存在大量的远红外跃迁偶极矩，我们估计所研究的量子阱的远红外跃迁偶极矩为1.05 μ m。我们的研究结果可能会被证明是重要的远红外探测器和发射器的设计。
We have induced ultrafast charge oscillations in the plane of an unbiased and undoped (110)-oriented GaAs quantum well by coherent optical excitation of heavy-hole and light-hole exciton transitions. The oscillations arise from an in-plane charge displacement between heavy-hole and light-hole states, which results from the periodic parts of the Bloch wave functions and the (110) orientation. The observations are evidence for the existence of a substantial far-infrared transition-dipole moment between heavy- and light-hole subbands for in-plane wave vectors, which we estimate to be ∼0.5Å for the quantum well under study. Our findings might prove important for designs of far-infrared detectors and emitters.