Fine structures of droplet-epitaxial GaAs/AlGaAs quantum dots under vertical electric fields

• Main Authors: Chou, Ying-Lin, 周穎霖
• Other Authors: Cheng, Shun-Jen
• Format: Others
• Language: zh-TW
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/72601292272543995295

碩士 === 國立交通大學 === 電子物理系所 === 102 === Generation of entangled photon pairs is a key element in quantum optics, communication and cryptography. Semiconductor quantum dots (QDs) are considered as an ideal entangled photon pair emitter due to their three-dimensional confinement of electrons and holes. In this thesis I theoretically investigate the energy spectra, optical polarizations and fine structure splittings of GaAs/AlGaAs quantum dots grown by droplet epitaxy (DE) under external vertical electric fields. We build up a theory for electron-hole exchange in the framework of multi band k.p theory. Compared with the widely studied InAs/GaAs self-assembled QDs, the sizes of DE-QDs are so large that the valence band mixing (VBM) is significant in the optical properties. The VBM effects on fine structure splittings (FSS), intensities and degrees of polarizations of the emitted photon pairs from the biased QDs are investigated.