Semiconductor quantum dots with light-hole exciton ground state: fabrication and fine structure
| Autor: | Huo, Y. H., Witek, B. J., Kumar, S., Singh, R., Zallo, E., Grifone, R., Kriegner, D., Trotta, R., Akopian, N., Stangl, J., Zwiller, V., Bester, G., Rastelli, A., Schmidt, O. G. |
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| Rok vydání: | 2012 |
| Předmět: | |
| Druh dokumentu: | Working Paper |
| Popis: | Quantum dots (QDs) can act as convenient hosts of two-level quantum szstems, such as single electron spins, hole spins or excitons (bound electron-hole pairs). Due to quantum confinement, the ground state of a single hole confined in a QD usually has dominant heavy-hole (HH) character. For this reason light-hole (LH) states have been largely neglected, despite the fact that may enable the realilzation of coherent photon-to-spin converters or allow for faster spin manipulation compared to HH states. In this work, we use tensile strains larger than 0.3% to switch the ground state of excitons confined in high quality GaAs/AlGaAs QDs from the conventional HH- to LH-type. The LH-exciton fine structure is characterized by two in-plane-polarized lines and, ~400 micro-eV above them, by an additional line with pronounced out-of-plane oscillator strength, consistent with theoretical predictions based on atomistic empirical pseudopotential calculations and a simple mesoscopic model. Comment: 16 pages, 4 figures |
| Databáze: | arXiv |
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