Polarized excitons in nanorings and the optical Aharonov-Bohm effect
Polarized excitons in nanorings and the optical Aharonov-Bohm effect
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DOI：
10.1103/physrevb.66.081309
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发表时间：
2002-08-15
影响因子：
3.7
通讯作者：
Warburton, RJ
中科院分区：
文献类型：
--
作者：
Govorov, AO;Ulloa, SE;Warburton, RJ
物质的量子本质在于当粒子沿其轨迹运动时积累的波函数相。一个突出的例子是Aharonov-Bohm相，它已经被研究与纳米结构的电导有关。然而，固体中的光学响应是由中性激发决定的，对磁通量不敏感。我们提出了一种中性粒子拓扑相的机制，它是一种限制在半导体量子环中的极化激子。我们预测，这种磁场诱导的相位可能会强烈影响柱对称系统中的激子，导致激子基态从“亮”态到具有几乎无限寿命的“暗”态之间的转换。由于激子决定了半导体的光学响应，预测的相位可以用来定制量子纳米结构的光子发射。
The quantum nature of matter lies in the wave function phases that accumulate while particles move along their trajectories. A prominent example is the Aharonov-Bohm phase, which has been studied in connection with the conductance of nanostructures. However, optical response in solids is determined by neutral excitations, for which no sensitivity to magnetic flux would be expected. We propose a mechanism for the topological phase of a neutral particle, a polarized exciton confined to a semiconductor quantum ring. We predict that this magnetic-field induced phase may strongly affect excitons in a system with cylindrical symmetry, resulting in switching between "bright" exciton ground states and novel "dark" states with nearly infinite lifetimes. Since excitons determine the optical response of semiconductors, the predicted phase can be used to tailor photon emission from quantum nanostructures.