Dataset Information

Transmission eigenvalue distributions in highly conductive molecular junctions.

ABSTRACT:

Background

The transport through a quantum-scale device may be uniquely characterized by its transmission eigenvalues ?(n). Recently, highly conductive single-molecule junctions (SMJ) with multiple transport channels (i.e., several ?(n) > 0) have been formed from benzene molecules between Pt electrodes. Transport through these multichannel SMJs is a probe of both the bonding properties at the lead-molecule interface and of the molecular symmetry.

Results

We use a many-body theory that properly describes the complementary wave-particle nature of the electron to investigate transport in an ensemble of Pt-benzene-Pt junctions. We utilize an effective-field theory of interacting ?-electrons to accurately model the electrostatic influence of the leads, and we develop an ab initio tunneling model to describe the details of the lead-molecule bonding over an ensemble of junction geometries. We also develop a simple decomposition of transmission eigenchannels into molecular resonances based on the isolated resonance approximation, which helps to illustrate the workings of our many-body theory, and facilitates unambiguous interpretation of transmission spectra.

Conclusion

We confirm that Pt-benzene-Pt junctions have two dominant transmission channels, with only a small contribution from a third channel with ?(n) << 1. In addition, we demonstrate that the isolated resonance approximation is extremely accurate and determine that transport occurs predominantly via the HOMO orbital in Pt-benzene-Pt junctions. Finally, we show that the transport occurs in a lead-molecule coupling regime where the charge carriers are both particle-like and wave-like simultaneously, requiring a many-body description.

SUBMITTER: Bergfield JP

PROVIDER: S-EPMC3304317 | biostudies-literature | 2012

REPOSITORIES: biostudies-literature

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Publications

Transmission eigenvalue distributions in highly conductive molecular junctions.

Bergfield Justin P JP Barr Joshua D JD Stafford Charles A CA

Beilstein journal of nanotechnology 20120116

<h4>Background</h4>The transport through a quantum-scale device may be uniquely characterized by its transmission eigenvalues τ(n). Recently, highly conductive single-molecule junctions (SMJ) with multiple transport channels (i.e., several τ(n) > 0) have been formed from benzene molecules between Pt electrodes. Transport through these multichannel SMJs is a probe of both the bonding properties at the lead-molecule interface and of the molecular symmetry.<h4>Results</h4>We use a many-body theory ...[more]

PMID: 22428095

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Dataset Information

Transmission eigenvalue distributions in highly conductive molecular junctions.

Background

Results

Conclusion

Publications

Transmission eigenvalue distributions in highly conductive molecular junctions.

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