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Lower bound for the excitonic fine structure splitting in self-assembled quantum dots
1Max-Planck-Institut für Festkörperforschung, Heisenbergstrasse 1, 70569 Stuttgart, Germany.
Physical Review Letters
|September 28, 2010
Summary
Excitonic fine structure splitting in quantum dots arises from lattice symmetry and electron-hole interactions. Our study reveals a fundamental lower bound for this splitting in realistic quantum dot structures.
Area of Science:
- Quantum Optics
- Condensed Matter Physics
- Materials Science
Background:
- Excitonic fine structure splitting is a key property of quantum dots.
- This splitting arises from atomistic lattice symmetry and electron-hole exchange interactions.
- Eliminating this splitting is crucial for quantum dot applications in quantum optics.
Purpose of the Study:
- To investigate the existence of a lower bound for excitonic fine structure splitting in realistic quantum dot structures.
- To understand the fundamental limits imposed by material properties on controlling quantum dot behavior.
Main Methods:
- Million atom empirical pseudopotential calculations.
- Symmetry analysis to underpin numerical findings.
Main Results:
- Demonstrated that a lower bound for excitonic fine structure splitting exists for realistic quantum dot structures.
- Provided a theoretical framework supported by numerical evidence.
Conclusions:
- The natural splitting of bright excitons in quantum dots cannot be entirely eliminated due to inherent material properties.
- This finding has implications for the design and application of quantum dots in quantum information processing and quantum optics.
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