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arXiv · 0705.3880

Fine-structure splitting of exciton states in quantum dot molecules: symmetry and tunnel-coupling effects

Dong Xu·Nan Zhao·Jia-Lin Zhu
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Abstract

Exciton levels and fine-structure splitting in laterally-coupled quantum dot molecules are studied. The electron and hole tunneling energies as well as the direct Coulomb interaction are essential for the exciton levels. It is found that fine-structure splitting of the two-lowest exciton levels is contributed from the intra- and inter-dot exchange interactions, both of which are largely influenced by the symmetry and tunnel-coupling between the two dots. As the inter-dot separation is reduced, fine-structure splitting of the exciton ground state is largely increased while those of the excited states are decreased. Moreover, the dependence of the fine-structure splitting in quantum dot molecules on the Coulomb correlation is clearly clarified.

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Dong Xu, Nan Zhao, Jia-Lin Zhu. 2007-06-25. Fine-structure splitting of exciton states in quantum dot molecules: symmetry and tunnel-coupling effects. https://doi.org/10.1088/0953-8984%2F20%2F04%2F045204

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