Optical emission from a charge-tunable quantum ring
| Autor: | Khaled Karrai, Winston V. Schoenfeld, F. Bickel, C. Schäflein, D. Haft, Jorge M. Garcia, Pierre Petroff, Axel Lorke, R. J. Warburton |
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| Rok vydání: | 2000 |
| Předmět: |
Multidisciplinary
Photoluminescence Band gap Chemistry business.industry Exciton Physics::Optics Electron Physik (inkl. Astronomie) Condensed Matter::Mesoscopic Systems and Quantum Hall Effect Condensed Matter::Materials Science Semiconductor Quantum dot laser Quantum dot Electro-absorption modulator Atomic physics business |
| Zdroj: | Digital.CSIC. Repositorio Institucional del CSIC instname |
| Popis: | 4 páginas, 4 figuras. Quantum dots or rings are artificial nanometre-sized clusters that confine electrons in all three directions. They can be fabricated in a semiconductor system by embedding an island of low-bandgap material in a sea of material with a higher bandgap. Quantum dots are often referred to as artificial atoms because, when filled sequentially with electrons, the charging energies are pronounced for particular electron numbers1, 2, 3; this is analogous to Hund's rules in atomic physics. But semiconductors also have a valence band with strong optical transitions to the conduction band. These transitions are the basis for the application of quantum dots as laser emitters4, storage devices5, 6, 7 and fluorescence markers8. Here we report how the optical emission (photoluminescence) of a single quantum ring changes as electrons are added one-by-one. We find that the emission energy changes abruptly whenever an electron is added to the artificial atom, and that the sizes of the jumps reveal a shell structure. This work was supported by the Deutsche Forschungsgemeinschaft and by QUEST, an NSF Science and Technology Center. |
| Databáze: | OpenAIRE |
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