Berlin 2008 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 20: Transport: Nanoelectronics I - Quantum Dots, Wires, Point Contacts 1
TT 20.5: Vortrag
Dienstag, 26. Februar 2008, 15:15–15:30, EB 202
Cross-Correlations in transport through two parallel quantum dots — •Sebastian Haupt1,2, Jasmin Aghassi1, Matthias Hettler2, and Gerd Schön1,2 — 1Institut für theoretische Festkörperphysik, Universität Karlsruhe, 76218 Karlsruhe — 2Forschungszentrum Karlsruhe, INT, Postfach 3640, 76201 Karlsruhe
We study cross-correlations of currents through two parallel quantum dots coupled to four independent electrodes. The quantum dots are coupled by intra-dot Coulomb interactions but tunneling between the dots is forbidden. The transport is calculated within second-order pertubation expansion in the coupling Γ to the electrodes within a diagrammatic technique. We allow for an intermediate coupling regime up to coupling constants of Γ ∼ kB T (where kb is the Boltzmann constant and the temperature is T). The level energy of the two quantum dots can be independently controlled via gate voltages. [1,2] The cross-correlations show different signs depending on the relation of transport process through the dots. For higher temperatures, the regions of equal sign have a spherical shape, whereas at lower temperature, an anglular “L-shape” is observed. This can be explained by the analysis of the relevant transport processes.
[1] D.T. McClure et al., Phys. Rev. Lett. 98, 056801 (2007)
[2] J. Aghassi et al., Appl. Phys. Lett. 89, 052101 (2006), Phys. Rev.B 73, 195323 (2006)