Optical anisotropy of unstrained GaAs/AlGaAs quantum dots in [111] growth direction
碩士 === 國立交通大學 === 電子物理系所 === 101 === Polarization-entangled pairs are a key element in the field of quantum information. The condition for generating polarization-entangled pairs is that fine structure splitting (FSS) must be smaller than the linewidth(~1μeV); however, many factors like shape, strai...
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| Format: | Others |
| Language: | zh-TW |
| Published: |
2013
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| Online Access: | http://ndltd.ncl.edu.tw/handle/02637244210749782872 |
| Summary: | 碩士 === 國立交通大學 === 電子物理系所 === 101 === Polarization-entangled pairs are a key element in the field of quantum information. The condition for generating polarization-entangled pairs is that fine structure splitting (FSS) must be smaller than the linewidth(~1μeV); however, many factors like shape, strain, atomic diffusion may increase FSS. And unstrained GaAs/AlGaAs quantum dots (QDs) is an excellent candidate easy to study due to nearly pure shape effect.
Valence band mixing (VBM) plays a crucial role on optical polarization (DOP) and FSS. In this thesis, studying by using simple model how growth directions or bright-exciton (BX) and dark-exciton (DX) coupling affect component of light-hole (LH) of QDs, further changing DOP. The results show DOP in the [111] direction is smaller than the one in the [001] direction and BX-DX coupling is weak without magnetic field.
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