Effects of time-dependent perturbations on the electron transport through single molecules

• Applicant: Professor Dr. Ulrich Kleinekathöfer
• Subject Area: Theoretical Condensed Matter Physics
• Term: from 2006 to 2015
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 24982018

The goal of this project is to investigate the possible influences which ultra-fast laser pulses can have on the electron transport through single molecules connected to two electron reservoirs. So far mainly the influence of monochromatic laser fields has been studied theoretically. Experimentally even less has been shown due to the complexity of the necessary setup. The theoretical foundation used for the present studies is a density matrix formalism where the full system is partitioned into a relevant part, i.e. the single molecule and fermionic reservoirs mimicking the leads. The employed quantum master equation incorporates the interaction with time-dependent laser fields non-perturbatively and is valid at low temperatures and weak molecule-lead coupling. In previous work an expression for the current under the influence of short laser pulses has been derived and tested. This approach has many extension possibilities and can point towards possible experimental realizations of current control through the molecular wire by ultra-fast laser pulses. Therefore we want to combine the already existing formalism with the optimal control theory, include electron correlation and a coupling to a thermal bath describing relaxation processes. Furthermore we want to improve the Hamiltonian to better describe realistic systems by, among other things, making close contact to ab initio simulations.

• DFG Programme: Priority Programmes
• Subproject of: SPP 1243: Quantum Transport at the Molecular Scale