Adiabatic time-dependent transport through single molecule transistors: interaction- and higher-order tunneling effects

• Applicant: Professorin Dr. Janine Splettstößer
• Subject Area: Theoretical Condensed Matter Physics
• Term: from 2006 to 2015
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 25049757

Single molecule devices offer interesting and important perspectives for future electronic circuits [1]. Fundamental questions regarding how current flows through a single molecule are closely related to the mechanical degrees of freedom which distinguish single-molecule devices from artificially created nano-devices such as quantum dots. New spectacular effects as, for instance, Franck-Condon resonances and negative differential conductance (NDC) were recently observed in single-molecule devices with a strong coupling of their quantized mechanical motion to the sequential tunneling current. Vibration related resonances were also observed in regimes where the sequential tunneling is suppressed by electron-electron interactions. Here correlated tunneling processes involving two electrons carry the current for sufficiently strong tunnel coupling. The goal of this project is to further develop the real-time transport theory for this vibration-assisted co-tunneling for typical experimental conditions: strong electron-electron and electron-vibration interaction and moderate (rather than weak) tunnel coupling compared to the temperature. This will enable the interpretation and direct analysis of experiments using models incorporating both experimentally known parameters and ab-initio input. It will give important direction and impetus for future experiments and for the development and control of single-molecule electro-mechanical devices.

• DFG Programme: Priority Programmes
• Subproject of: SPP 1243: Quantum Transport at the Molecular Scale
• Participating Person: Professor Dr. Maarten Rolf Wegewijs