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TT: Tiefe Temperaturen

TT 33: Transport - Nanoelectronics III: Molecular Electronics

TT 33.6: Talk

Tuesday, March 8, 2005, 15:15–15:30, TU H3027

Electron-phonon coupling mechanisms in molecular electron transport — •Michael Hartung — Institute for Theoretical Physics, University of Regensburg, D-93040 Regensburg, Germany

We study the conductance through a single vibrating molecule contacted to two metallic electrodes. The starting point is a tight-binding Hamiltonian with a linear coupling of the ionic motion to the electronic degrees of freedom. We distinguish between a coupling to the onsite energy of the molecule and a coupling representing a bond-stretching vibrational mode.

The full nonequilibrium current, shot noise, and dissipated power is calculated within the Keldysh Green function formalism. As far as transport observables are concerned, onsite and bond-stretching coupling mechanisms differ in several respects: In the latter case satellite peaks in the differential conductance are more pronounced and results closer to the experimental evidence can be obtained.