Dresden 2011 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 61: TR: Nanoelectronics I - Quantum Dots, Wires, Point Contacts 3

TT 61.2: Vortrag

Freitag, 18. März 2011, 10:45–11:00, HSZ 304

Negative differential conductance with symmetric set-up ? — •Andrea Donarini, Abdullah Yar, and Milena Grifoni — Universität Regensburg, Germany

We consider a minimal model of transport through a nano-junction in the single electron tunneling regime. We prove that the source-drain asymmetric is not a necessary condition for the appearance of negative differential conductance (NDC). The latter is obtained even for a completely symmetric set up under specific conditions over the "geometrical component" of the tunneling rates. We apply the theory to study the transport characteristics of suspended carbon nanotube quantum dots. The electron-phonon coupling tunes in this case the "geometrical component" of the rates and determines the presence of NDC. Moreover, the interplay of Franck-Condon factors and spin/pseudo-spin degeneracies generates gate asymmetries in the stability diagram.