Regensburg 2010 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 11: Transport

HL 11.5: Vortrag

Montag, 22. März 2010, 15:00–15:15, H14

Fast initialization of dynamic quantum dots — •Philipp Mirovsky, Bernd Kaestner, Christoph Leicht, Klaus Pierz, Thomas Weimann, and Hans Werner Schumacher — PTB, 38116 Braunschweig, Germany

We present experimental studies on dynamic quantum dots, formed within non adiabatic single electron pumps. We employ etched AlGaAs/GaAs nanowires crossed by three metal top gates, set to negative voltages to define a dot. By applying radio frequency signals of frequency f to the outermost gate, electrons are pumped through the dot. Directly after the loading electrons from source into the dot it is decoupled from the environment. The electron number is controlled by a plunger gate. During the second half of the cycle the pump transports the electrons previously loaded inside the dot to drain. Measuring the produced pumping current divided by e*f we obtain the population of the dot averaged over many cycles. In this way we are able to study the initialization conditions without the need for other single-charge detector system. This pumping mechanism also represents an alternative path to the realization of a high current high accuracy quantum standard for electrical current.