114 research outputs found
Numerically exact, time-dependent study of correlated electron transport in model molecular junctions
The multilayer multiconfiguration time-dependent Hartree theory within second
quantization representation of the Fock space is applied to study correlated
electron transport in models of single-molecule junctions. Extending previous
work, we consider models which include both electron-electron and
electronic-vibrational interaction. The results show the influence of the
interactions on the transient and the stationary electrical current. The
underlying physical mechanisms are analyzed in conjunction with the
nonequilibrium electronic population of the molecular bridge.Comment: arXiv admin note: substantial text overlap with arXiv:1103.494
Charge transport through a flexible molecular junction
Vibrationally inelastic electron transport through a flexible molecular
junction is investigated. The study is based on a mechanistic model for a
biphenyl molecule between two metal electrodes. Employing methods from
electron-molecule scattering theory, which allow a numerically exact treatment,
we study the effect of vibrational excitation on the transmission probability
for different parameter regimes. The current-voltage characteristic is analyzed
for different temperatures, based on a Landauer-type formula. Furthermore, the
process of electron assisted tunneling between adjacent wells in the torsional
potential of the molecule is discussed and the validity of approximate methods
to describe the transmission probability is investigated.Comment: 14 pages, Submited to Czech. J. Phy
Hierarchical quantum master equation approach to charge transport in molecular junctions with time-dependent molecule-lead coupling strengths
Time-dependent currents in molecular junctions can be caused by structural
fluctuations or interaction with external fields. In this publication, we
demonstrate how the hierarchical quantum master equation approach can be used
to study time-dependent transport in a molecular junction. This reduced density
matrix methodology provides a numerically exact solution to the transport
problem including time-dependent energy levels, molecule-lead coupling
strengths and transitions between electronic states of the molecular bridge.
Based on a representative model, the influence of a time-dependent
molecule-lead coupling on the electronic current is analyzed in some detail
- …