arXiv subjects

Alexander Schnurpfeil

Publications and source records attributed to Alexander Schnurpfeil.

3 recordsLinked to original sources

arXiv2005

A wave function based ab initio non-equilibrium Green's function approach to charge transport

We present a novel ab initio non-equilibrium approach to calculate the current across a molecular junction. The method rests on a wave function based description of the central region of the junction combined with a tight binding approximation for the electrodes in the frame of the Keldysh Green's function formalism. In addition we present an extension so as to include effects of the two-particle propagator. Our procedure is demonstrated for a dithiolbenzene molecule between silver electrodes. The full current-voltage characteristic is calculated. Specific conclusions for the contribution of correlation and two-particle effects are derived. The latter are found to contribute about 5% to the current. The order of magnitude of the current coincides with experiments.

cond-mat.mtrl-sci↗

arXiv2005

Charge Transport Properties of Molecular Junctions built from Dithiol Polyenes

We present a study of the charge transmission behavior of a series of dithiol polyenes in the context of molecular junctions. Using the Landauer theory and zero voltage approximation the Green's functions of the inserted molecules are calculated from a fully ab initio wave function based procedure. Various possibilities in approximating the correlation space are explored and quantitatively evaluated. Our results show that the transmission behavior of a molecular junction is not a monotonic function of the length of the employed molecule. Moreover we introduce the analytic solution of a suitable model system to countercheck the ab initio results and find a remarkable degree of correspondence.

cond-mat.mtrl-sci↗

arXiv2005

An ab initio non-equilibrium Green's function approach to charge transport: dithiolethine

We present a novel ab initio non-equilibrium approach to calculate the current across a molecular junction. The method rests on a wave function based full ab initio description of the central region of the junction combined with a tight binding approximation for the electrodes in the frame of the Keldysh Green's function formalism. Our procedure is demonstrated for a dithiolethine molecule between silver electrodes. The main conducting channel is identified and the full current-voltage characteristic is calculated.

cond-mat.mtrl-sci↗