Physik-Department, Technische Universität München, James-Franck-Straße 1, D-85748 Garching, Germany.
J Phys Condens Matter. 2013 Sep 25;25(38):385301. doi: 10.1088/0953-8984/25/38/385301. Epub 2013 Aug 29.
We examine theoretically the intersubband transitions induced by laser beams of light with orbital angular momentum (twisted light) in semiconductor quantum wells at normal incidence. These transitions become possible in the absence of gratings thanks to the fact that collimated laser beams present a component of the light's electric field in the propagation direction. We derive the matrix elements of the light-matter interaction for a Bessel type twisted light beam represented by its vector potential in the paraxial approximation. Then, we consider the dynamics of photoexcited electrons making intersubband transitions between the first and second subbands of a standard semiconductor quantum well. Finally, we analyze the light-matter matrix elements in order to evaluate which transitions are more favorable for a given orbital angular momentum of the light beam in the case of small semiconductor structures.
我们从理论上研究了在垂直入射下，半导体量子阱中轨道角动量（扭曲光）激光束诱导的子带间跃迁。由于准直激光束在传播方向上存在电场分量，因此在没有光栅的情况下，这些跃迁成为可能。我们在傍轴近似下，用矢势表示贝塞尔型扭曲光束，推导出光物质相互作用的矩阵元。然后，我们考虑在标准半导体量子阱中，电子从第一子带跃迁到第二子带的光激发动力学。最后，我们分析光物质矩阵元，以评估在小半导体结构的情况下，给定光束的轨道角动量，哪些跃迁更有利。
