Dresden 2009 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 39: Quantum dots: Optical and transport properties

HL 39.10: Vortrag

Donnerstag, 26. März 2009, 12:15–12:30, BEY 81

Single-parameter quantized charge pumping in magnetic fields — •Christoph Leicht¹, Bernd Kaestner¹, Vyacheslavs Kashcheyevs^2,3, Klaus Pierz¹, Uwe Siegner¹, and Hans Werner Schumacher¹ — ¹Physikalisch-Technische Bundesanstalt, Bundesallee 100, 38116 Braunschweig, Germany — ²Institute for Solid State Physics, University of Latvia, Riga LV-1063, Latvia — ³Faculty of Physics and Mathematics, University of Latvia, Zellu street 8, Riga LV-1002, Latvia

We present a study of high frequency quantized charge pumping through a GaAs/AlGaAs quantum dot in the presence of a perpendicular magnetic field. Application of a frequency signal in the GHz-range to one of two finger gates, crossing a narrow wire and confining a quantum dot, leads to quantized, pumped current plateaus in the gate characteristics. Magnetic fields up to around 6 T considerably enhance the quality and the number of observed current plateaus. A dimensionless quality factor is determined to rate the flatness of the first plateau and to indicate the achievable accuracy for metrological purposes.