Dresden 2017 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 69: Quantum Dots: Transport Properties I

HL 69.2: Talk

Thursday, March 23, 2017, 09:45–10:00, POT 151

Influence of Dimensionality on Tunneling into a Quantum Dot — •Jan K. Kühne and Rolf J. Haug — Institut für Festkörperphysik, Leibniz Universität Hannover, Deutschland

We study the transport properties of a system of self-assembled InAs quantum dots at low temperatures. Especially, we investigate the influence of the dimensionality of the connected leads on the tunneling into a dot. The transport properties depend on a variety of parameters, such as temperature, size of the dots, magnetic field and the thickness of the tunneling barriers. Measuring shot noise reveals more information about our system than a current or conductance measurement alone. In particular the asymmetry of the tunneling rates can only be observed in the noise signal. Additionally, interaction effects between electrons are known to suppress or enhance shot noise [1].
By changing the current directions of our sample we encounter different behavior of the Fano factor and the shape of the resonance step. This can be explained by a change of dimensionality in the leads and therefore another density of states. By using a Master equation theory we are able to extract the corresponding tunneling rates from our measurements [2]. Further, we are interested in the effect of an applied magnetic field on the transport and noise behavior of our system.
A. Nauen, et al., Phys. Rev. B 70, 033305 (2004).
G. Kiesslich, et al., Phys. Rev. B 68, 125320 (2003).