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HL: Fachverband Halbleiterphysik
HL 24: Quantum dots and wires: Transport properties II
HL 24.4: Vortrag
Dienstag, 27. März 2007, 14:45–15:00, H15
Full counting statistics on a single dot device — •C. Fricke1, F. Hohls1, M. Reinwald2, W. Wegscheider2, and R. J. Haug1 — 1Institut für Festkörperphysik, Leibniz Universität Hannover, D-30167 Hannover — 2Angewandte und Experimentelle Physik, Universität Regensburg, D-93040 Regensburg
We show full counting statistics analysis on a coupled system including a quantum dot and a quantum point contact. We use a GaAs / AlGaAs heterostructure containing a two-dimensional electron system (2DES) 34 nm below the surface. The lateral quantum dot and the quantum point contact (QPC) are defined by the atomic force microscope (AFM) using local anodic oxidation (LAO). Our device allows us to control independently the quantum point contact and all tunnelling barriers of the quantum dot. We perform time resolved measurements [1] of the current through the QPC detector. We are able to detect individual electrons entering or leaving the dot up to a tunnelling rate of 30 KHz. We use these features to directly analyze counting statistic of single electrons passing through the quantum dot [2].
[1] L. M. K. Vandersypen et al., Appl. Phys. Lett. 85, 4394 (2004)
[2] S. Gustavsson et al., Phys. Ref. Lett. 96, 076605 (2006)