Regensburg 2010 – scientific programme
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HL: Fachverband Halbleiterphysik
HL 31: Poster I: Devices, Quantum Dots and Quantum Wires
HL 31.28: Poster
Tuesday, March 23, 2010, 18:30–20:30, Poster D1
Noise measurements of a quantized charge pump — •Lukas Fricke1, Niels Maire1, Frank Hohls1, Bernd Kästner2, Christoph Leicht2, Philipp Mirovsky2, Hans Werner Schumacher2, and Rolf J. Haug1 — 1Institut für Festkörperphysik, Leibniz Universität Hannover, Appelstr. 2, 30167 Hannover — 2Physikalisch-Technische Bundesanstalt, Bundesallee 100, 38116 Braunschweig
Delivering a quantized number of electrons per cycle in a reliable fashion and at high repetition rate could satisfy the need for a current-quantum standard. A promising candidate is the non-adiabatic electron pump in semiconductor nanostructures, especially considering parallelization of these devices for higher current outputs.
We performed low frequency (fn<10 kHz) current-noise measurements [1] of such a device at a pumping frequency of fp=600 MHz. We observe a strong suppression of the noise power when the current is quantized in good agreement with a prediction for an ideal pump whereas in the intermediate region between two quantization plateaus an enhanced noise power can be measured. With these measurements different pumping processes can be distinguished.
[1] N.Maire et al., Appl. Phys. Lett. 92, 082112 (2008)