Charge transport


People: Prof. Ulrich Kleinekathöfer, Bogdan Popescu, Hasan Rahman

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:

[101]   B. Popescu, H. Rahman and U. Kleinekathöfer, Using the Chebyshev Expansion in Quantum Transport Calculations, J. Chem. Phys. 142, 154103 (2015).

[90]    B. Popescu and U. Kleinekathöfer, Treatment of Time-dependent Effects in Molecular Junctions, phys. stat. sol. (b) 250, 2288–2297 (2013), special issue ’Quantum transport at the molecular scale’.

[89]    T. Kubař, R. Gutiérrez, U. Kleinekathöfer, G. Cuniberti and M. Elstner, Modeling Charge Transport in DNA Using Multi-scale Methods, phys. stat. sol. (b) 250, 2277–2287 (2013), special issue ’Quantum transport at the molecular scale’.

[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).