Journal article · Preprint article
Inelastic transport theory from first principles: Methodology and application to nanoscale devices
Theoretical Nanotechnology, Department of Micro- and Nanotechnology, Technical University of Denmark1
Department of Micro- and Nanotechnology, Technical University of Denmark2
Theoretical Nanoelectronics Group, Theory Section, Department of Micro- and Nanotechnology, Technical University of Denmark3
Theory Section, Department of Micro- and Nanotechnology, Technical University of Denmark4
We describe a first-principles method for calculating electronic structure, vibrational modes and frequencies, electron-phonon couplings, and inelastic electron transport properties of an atomic-scale device bridging two metallic contacts under nonequilibrium conditions. The method extends the density-functional codes SIESTA and TRANSIESTA that use atomic basis sets.
The inelastic conductance characteristics are calculated using the nonequilibrium Green’s function formalism, and the electron-phonon interaction is addressed with perturbation theory up to the level of the self-consistent Born approximation. While these calculations often are computationally demanding, we show how they can be approximated by a simple and efficient lowest order expansion.
Our method also addresses effects of energy dissipation and local heating of the junction via detailed calculations of the power flow. We demonstrate the developed procedures by considering inelastic transport through atomic gold wires of various lengths, thereby extending the results presented in Frederiksen et al.
Phys. Rev. Lett. 93, 256601 2004. To illustrate that the method applies more generally to molecular devices, we also calculate the inelastic current through different hydrocarbon molecules between gold electrodes. Both for the wires and the molecules our theory is in quantitative agreement with experiments, and characterizes the system-specific mode selectivity and local heating.
Language: | English |
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Year: | 2007 |
Pages: | 24 |
ISSN: | 1550235x , 10980121 and 01631829 |
Types: | Journal article and Preprint article |
DOI: | 10.1103/PhysRevB.75.205413 |
ORCIDs: | Brandbyge, Mads and Jauho, Antti-Pekka |
ATOMIC-SCALE CONDUCTORS ELECTRON-TUNNELING SPECTROSCOPY MANIPULATION MECHANISMS METAL-SURFACES MOLECULAR JUNCTIONS MONATOMIC GOLD WIRES PHONON INTERACTION SCATTERING SIMULATION