Berlin 2018 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 24: Poster Session II
HL 24.6: Poster
Dienstag, 13. März 2018, 18:30–20:30, Poster F
Tunneling rates of quantum dots for single electron pumps — •Tobias Wenz1, Friederike Stein1, Frank Hohls1, Hans Werner Schumacher1, Jevgeny Klochan2, and Vyacheslavs Kashcheyevs2 — 1Physikalisch-Technische Bundesanstalt (PTB), 38116 Braunschweig, Germany — 2Faculty of Physics and Mathematics, University of Latvia, LV 1002 Riga, Latvia
Quantum dots with tunable barriers can be used as single electron pumps. By capturing a well-defined number of electrons n from source and emitting them to drain with a high frequency f a quantized current I=nef is produced, where e is the electron charge [1]. This concept is useful for on-demand electron sources for electron quantum optics and for the redefinition of the ampere by fixing the value of e.
So far, mainly the back-tunneling process has been studied, as it is the limiting factor to the accuracy of a single-electron pump.
In this work, we study the loading of electrons into the dynamic quantum dot using custom-tailored waveforms.
This allows us to investigate in-tunneling rates to the dot and extract information on ground- and excited states.
Their dependencies are studied as a function of temperature and magnetic field.
Our goal is to extract an absolute energy scale that may be used for the description of the back-tunneling process, for example in the decay-cascade model [2].
Kaestner and Kashcheyevs, Rep. Prog. Phys. 78, 103901 (2015)
Kashcheyevs and Kaestner, Phys. Rev. Lett. 104, 186805 (2010)