| Autor: |
Jacob R; Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, P.O. Box 51 01 19, 01314 Dresden, Germany., Winnerl S, Fehrenbacher M, Bhattacharyya J, Schneider H, Wenzel MT, Ribbeck HG, Eng LM, Atkinson P, Schmidt OG, Helm M |
| Jazyk: |
angličtina |
| Zdroj: |
Nano letters [Nano Lett] 2012 Aug 08; Vol. 12 (8), pp. 4336-40. Date of Electronic Publication: 2012 Jul 11. |
| DOI: |
10.1021/nl302078w |
| Abstrakt: |
Using scattering-type near-field infrared microscopy in combination with a free-electron laser, intersublevel transitions in buried single InAs quantum dots are investigated. The experiments are performed at room temperature on doped self-assembled quantum dots capped with a 70 nm GaAs layer. Clear near-field contrast of single dots is observed when the photon energy of the incident beam matches intersublevel transition energies, namely the p-d and s-d transition of conduction band electrons confined in the dots. The observed room-temperature line width of 5-8 meV of these resonances in the mid-infrared range is significantly below the inhomogeneously broadened spectral lines of quantum dot ensembles. The experiment highlights the strength of near-field microspectroscopy by demonstrating signals from bound-to-bound transitions of single electrons in a probe volume of the order of (100 nm)(3). |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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