Charge transport


People: Prof. Ulrich Kleinekathöfer

Cooperations: Prof. Marcus Elstner, Dr. T. Kubař, Karlsruhe Institute of Technology

The study of time-dependent effects in the transport through molecular junctions is in the focus of this research line. Two different sources of time-dependent perturbations can be considered: fluctuations resulting from surrounding liquids and external (laser) fields. Surrounding liquid molecules such as water can lead to large and fast fluctuations of the site energies of the orbitals involved in the charge transfer. Therefore methods have to be further developed and employed to accurately and efficiently determine the charge current and noise in these cases. The fluctuations in the energies and couplings can be extracted from atomistic simulations. These parameters can then directly be used in transport calculations or first be transformed in so-called spectral densities which in turn can be used in calculations with time-independent Hamiltonians.

Previous funding by the DFG through priority program SPP 1243 Quantum Transport at the Molecular Scale.

Selected publications:

[132]   H. Rahman, P. Karasch, D. A. Ryndyk, T. Frauenheim and U. Kleinekathöfer, Dephasing in a Molecular Junction Viewed from a Time-Dependent and a Time-Independent Perspective, J. Phys. Chem. C 123, 9590–9599 (2019).

[129]   H. Rahman and U. Kleinekathöfer, Non-Equilibrium Green’s Function Transport Theory for Molecular Junctions with General Molecule-Lead Coupling and Temperatures, J. Chem. Phys. 149, 234 108 (2018).

[114]   M. Wolter, M. Elstner, U. Kleinekathöfer und T. Kubař, Microsecond Simulation of Electron Transfer in DNA: Bottom-up Parametrization of an Efficient Electron Transfer Model Based on Atomistic Details, J. Phys. Chem. B 121, 529–549 (2017).

[112]   T. Kubař, M. Elstner, B. Popescu and U. Kleinekathöfer, Polaron Effects on Charge Transport through Molecular Wires: A Multi-scale Approach, J. Chem. Theory Comput. 13, 286–296 (2017).

[84]    B. Popescu, P. B. Woiczikowski, M. Elstner and U. Kleinekathöfer, Time-Dependent View of Sequential Transport through Molecules with Rapidly Fluctuating Bridges, Phys. Rev. Lett. 109, 176 802 (2012).