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HL: Fachverband Halbleiterphysik

HL 19: Quantum dots and wires: Transport properties

HL 19.7: Vortrag

Dienstag, 13. März 2018, 11:00–11:15, A 151

Scaling of the Fermi-Edge-Singularity in Asymmetric Quantum Dots — •Jan K. Kühne and Rolf J. Haug — Institut für Festkörperphysik, Leibniz Universität Hannover, 30167 Hannover, Germany

We study the transport properties of a self-assembled InAs quantum dot at low temperatures. Transport properties depend on a variety of parameters, such as temperature, size of the dots, magnetic field and thickness of the two tunneling barriers. We focus on the influence of the dimensionality of the connected leads on the tunneling in and out of the quantum dot.

In dependence on the direction of current we encounter different transport behavior, especially under the influence of a magnetic field. This can be explained by a different density of states in the two leads. Further information is gained via shot noise measurements, which are known to reveal more about the correlation between electrons than current measurements alone; e.g. interaction effects have been shown to suppress or enhance shot noise [1]. The Fermi-edge-singularity (FES) is one example, where interaction between the dot and the emitter electrons can lead to a Fano-factor larger than one [2]. To study the FES in more detail we use a scaling function approach introduced by H. Frahm [3] to analyze the temperature-dependent current resonance.

[1] H. C. Liu, et al., Phys. Rev. B 51, 5116 (1995).

[2] N. Ubbelohde, et al., Scientific Reports 2, 374 (2012).

[3] H. Frahm, et al., Phys. Rev. B 74, 35329 (2006).