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HL: Halbleiterphysik
HL 49: Poster II
HL 49.40: Poster
Donnerstag, 27. März 2003, 16:30–19:00, HSZ/P2
Shot noise properties of self-assembled InAs quantum dots — •Niels Maire1, André Nauen1, Frank Hohls1, Rolf J. Haug1, and Klaus Pierz2 — 1Universität Hannover, Institut für Festkörperphysik, Abteilung Nanostrukturen, Appelstr. 2, D-30167 Deutschland — 2Physikalisch-Technische Bundesanstalt, Bundesallee 100, D-38116 Deutschland
We present noise measurements on resonant single electron tunnelling through individual quantum dots (QDs). Our samples consist of a GaAs-AlAs-GaAs tunnelling structure with embedded InAs QDs. The resulting I-V curve is a step-like function where every current plateau can be linked to a single QD.[1] Analyzing the dependence of the shot noise as a function of bias voltage we observe an increase in between two current plateaus.[2] In contrast, on every plateau, where the current is determined by tunnelling through a single dot, we find a minimum of α. The suppression of shot noise when the current flows through a resonant state is in agreement with theoretical predictions [3]. Additionally the behaviour of the Fano factor off resonance is discussed.
[1] I. Hapke-Wurst, U. Zeitler, H. Frahm, A. G. M. Jansen, R. J. Haug and K. Pierz, Phys. Rev. B 62, 12621 (2000)
[2] A. Nauen, I. Hapke-Wurst, F. Hohls, U. Zeitler, R. J. Haug and K. Pierz, Phys. Rev. B 66, 161303(R) (2002)
[3] Ya. M. Blanter and M. Büttiker, Phys. Rep. 336, 1 (2000) and references therein