Objective:
- Understand experimental data on QD spectra fine structure
- Px and Py states are split in energy –
Why – critical physical items
Approach:
- Implement piezo-electric charges through electrostatic potential
- Compare effects of
- Crystal Symmetry
- Strain
- Piezoelectricity
- Disk shaped dots d=10nm, h=2.5nm, 10nm cap, 20nm substrate, 0.6nm wetting layer
Impact:
- Demonstrated quantitative agreement with experiment
- Atomistic approach is essential
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Impact:
- Crystal symmetry alone breaks symmetry of set of first excited states (weak)
- Strain breaks symmetry stronger
- => effective mass, k.p fail!Piezoelectric effect opposes strain
- => can flip orientation of the excited state
Publication:
- Accepted in accepted in Springer Encyclopedia for Complexity, 2008 [J_2008_14].
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