Berlin 2012 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 69: Quantum Dots and Wires: Transport Properties II (mainly Quantum Dots)

HL 69.2: Vortrag

Mittwoch, 28. März 2012, 17:30–17:45, EW 203

A self-referenced single-electron current source — •Lukas Fricke, Michael Wulf, Frank Hohls, Bernd Kaestner, Ralf Dolata, Philipp Mirovsky, Klaus Pierz, Thomas Weimann, and Hans W. Schumacher — Physikalisch-Technische Bundesanstalt, Bundesallee 100, D-38116 Braunschweig

A promising candidate for a quantum-based current source is the non-adiabatic electron pump [1], based on a dynamic quantum dot in a semiconducting nanostructure. High current outputs [2] and parallelization [3] for further increased currents have been demonstrated. However, to employ this device as a new current standard or as an on-demand electron source, a high pumping reliability and therefore a measure of single-electron pump accuracy is needed.

We demonstrate a mesoscopic circuit employing a series of semiconducting dynamic quantum dots in combination with metallic single electron transistors (SET) able to monitor the electrostatic potential between the pumps on the single-electron level and thereby individual pump errors. We operate the pumps in a single-shot mode, pumping one electron from node to node with a fidelity verified by the SETs. The rare pump errors can be identified and attributed to each pump so that the compound device acts as a highly accurate self-referenced quantum current source [4].

[1] B. Kaestner et al., Phys. Rev. B 77, 153301 (2008)

[2] M. D. Blumenthal et al., Nat. Phys. 3, 343 (2007)

[3] P. Mirovsky et al., Appl. Phys. Lett. 97, 252104 (2010)

[4] M. Wulf and A. B. Zorin, e-print arXiv:0811.3927