Inelastic transport theory from first-principles: methodology and applications for nanoscale devices

Abstract

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.

24 pages, 17 figures

References in corpus (7)

• Electrical generation and absorption of phonons in carbon nanotubes
• Vibrational sidebands and dissipative tunneling in molecular transistors
• Inelastic scattering and local heating in atomic gold wires
• Modeling inelastic phonon scattering in atomic- and molecular-wire junctions
• Contact Atomic Structure and Electron Transport Through Molecules
• Coulomb blockade in electron transport through a C${}_{60}$ molecule from first principles
• Modeling of inelastic transport in one-dimensional metallic atomic wires

Cited by in corpus (8)

• Molecular Transport Junctions: Vibrational Effects
• Unified description of inelastic propensity rules for electron transport through nanoscale junctions
• Phonon-assisted current noise in molecular junctions
• Coupled electron and phonon transport in one-dimensional atomic junctions
• From tunneling to contact: Inelastic signals in an atomic gold junction
• Dynamic Jahn-Teller effect in electron transport through single C60 molecules
• Inelastic quantum transport: the self-consistent Born approximation and correlated electron-ion dynamics
• Ab initio study of charge transport through single oxygen molecules in atomic aluminum contacts