標題: | Geometrical impact on the optical polarization of droplet epitaxial quantum dots |
作者: | Liao, Yu-Huai Liao, Chien-Chih Ku, Chih-Hao Chang, Yu-Chen Cheng, Shun-Jen Jo, Masafumi Kuroda, Takashi Mano, Takaaki Abbarchi, Marco Sakoda, Kazuaki 電子物理學系 Department of Electrophysics |
公開日期: | 17-九月-2012 |
摘要: | We report on experimental and theoretical investigations of the optical anisotropy of GaAs/AlGaAs quantum dots grown by droplet epitaxy. With in situ annealing in the growth, the shape of quantum dots is systematically controlled from a tall and laterally symmetric shape to a flat and laterally elongated one. Photoluminescence spectroscopy demonstrates an uncommon observation: the more elongated the quantum dots, the lower the degree of linear polarization. Theoretical analysis based on a four-band k center dot p theory reveals a substantial impact of vertical confinement on the valence heavy-hole and light-hole mixing, which leads to the enhancement of polarization anisotropy for taller quantum dots. The influence of Coulomb interactions on polarization anisotropy is studied by using the partial configuration interaction method, and is shown to reduce the polarization anisotropy through the mixing of single-particle configurations with different symmetries. |
URI: | http://dx.doi.org/10.1103/PhysRevB.86.115323 http://hdl.handle.net/11536/16848 |
ISSN: | 1098-0121 |
DOI: | 10.1103/PhysRevB.86.115323 |
期刊: | PHYSICAL REVIEW B |
Volume: | 86 |
Issue: | 11 |
起始頁: | 0 |
結束頁: | 0 |
顯示於類別: | 期刊論文 |