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TT: Fachverband Tiefe Temperaturen
TT 33: TR: Nanoelectronics I: Quantum Dots, Wires, Point Contacts 2
TT 33.4: Vortrag
Donnerstag, 25. März 2010, 14:45–15:00, H19
Competing carbon nanotube quantum dots with different screening properties — •Karin Goß1,3, Carola Meyer1,3, Maarten R. Wegewijs2,3, and Claus M. Schneider1,3 — 1Institute of Solid State Research (IFF-9), Forschungszentrum Jülich, 52425 Jülich, Germany — 2Institute of Solid State Research (IFF-3), Forschungszentrum Jülich, 52425 Jülich, Germany — 3JARA Jülich Aachen Research Alliance
We report quantum transport measurements on a carbon nanotube (CNT) quantum dot in the single electron tunneling regime. In addition to standard nanotube shell-filling effects, the stability diagram shows resonances in the Coulomb blockade regime. These resonances are not due to inelastic cotunneling through a single CNT as their finite slope and anomalous anticrossing with the diamond edges indicate. Instead, atomic force microscopy images suggest that the contacted device consists of a rope of nanotubes, based on the rather large diameter of ca. 7nm. In a constant interaction picture the observed transport phenomena can be attributed to two nanotubes acting as coupled quantum dots. The anticrossings of the additional resonances with the diamond edges indicate hybridization of states of the two dots. The difference of both the asymmetry of tunneling and screening properties between the two dots allows this hybridization to be probed.