Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userThermally induced charge current through long molecules
89
0
0.0
(
0
)
Added by
Natalya A. Zimbovskaya
Publication date
2017
fields
Physics
and research's language is
English
Ask ChatGPT about the research
No Arabic abstract
In this work we theoretically study steady state thermoelectric transport through a single-molecule junction with a long chain-like bridge. Electron transmission through the system is computed using a tight-binding model for the bridge. We analyze dependences of thermocurrent on the bridge length in unbiased and biased systems operating within and beyond linear response regime. It is shown that length-dependent thermocurrent is controlled by the lineshape of electron transmission in the interval corresponding to HOMO/LUMO transport channel. Also, it is demonstrated that electron interactions with molecular vibrations may significantly affect length-dependent thermocurrent.
rate research
Read More
Anisotropic single-molecule magnets may be thought of as molecular switches, with possible applications to molecular spintronics. In this paper, we consider current-induced switching in single-molecule junctions containing an anisotropic magnetic molecule. We assume that the carriers interact with the magnetic molecule through the exchange interaction and focus on the regime of high currents in which the molecular spin dynamics is slow compared to the time which the electrons spend on the molecule. In this limit, the molecular spin obeys a non-equilibrium Langevin equation which takes the form of a generalized Landau-Lifshitz-Gilbert equation and which we derive microscopically by means of a non-equilibrium Born-Oppenheimer approximation. We exploit this Langevin equation to identify the relevant switching mechanisms and to derive the current-induced switching rates. As a byproduct, we also derive S-matrix expressions for the various torques entering into the Landau-Lifshitz-Gilbert equation which generalize previous expressions in the literature to non-equilibrium situations.
The charge flow from a single C60 molecule to another one has been probed. The conformation and electronic states of both molecules on the contacting electrodes have been characterized using a cryogenic scanning tunneling microscope. While the contact conductance of a single molecule between two Cu electrodes can vary up to a factor of three depending on electrode geometry, the conductance of the C60-C60 contact is consistently lower by two orders of magnitude. First-principles transport calculations reproduce the experimental results, allow a determination of the actual C60-C60 distances, and identify the essential role of the intermolecular link in bi- and trimolecular chains.
We investigate electronic transport through two types of conjugated molecules. Mechanically controlled break-junctions are used to couple thiol endgroups of single molecules to two gold electrodes. Current-voltage characteristics (IVs) of the metal-molecule-metal system are observed. These IVs reproduce the spatial symmetry of the molecules with respect to the direction of current flow. We hereby unambigously detect an intrinsic property of the molecule, and are able to distinguish the influence of both the molecule and the contact to the metal electrodes on the transport properties of the compound system.
The single-molecule conductance of a 3-ring, conjugated azomethine was studied using the mechanically controlled breakjunction technique. Charge transport properties are found to be comparable to vinyl-based analogues; findings are supported with density functional calculations. The simple preparation and good transport properties make azomethine-based molecules an attractive class for use in polymer and single-molecule organic electronics.
We analyze the contribution of the inhomogeneous magnetic field induced by an electrical current to the spin Hall effect in metals. The Zeeman coupling between the field and the electron spin leads to a spin dependent force, and to spin accumulation at the edges. We compare the effect of this relativistic correction to the electron dynamics to the features induced by the spin-orbit interaction. The effect of current induced magnetic fields on the spin Hall effect can be comparable to the extrinsic contribution from the spin-orbit interaction, although it does not require the presence of heavy elements with a strong spin-orbit interaction. The induced spins are oriented normal to the metal slab.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
