Asymptotic self-consistency in quantum transport calculations

Abstract

Ab-initio simulations of quantum transport commonly focus on a central region which is considered to be connected to infinite, periodic leads through which the current flows. The electronic structure of these distant leads is normally obtained from an equilibrium calculation, ignoring the self-consistent response of the leads to the current. We examine the consequences of this, and show that the electrostatic potential is effectively being approximated by the difference between electrochemical potentials and that this approximation is incompatible with asymptotic charge neutrality. In a test calculation for a simple metal-vacuum-metal junction, we find large errors in the non-equilibrium properties calculated with this approximation, in the limit of small vacuum gaps. We provide a simple scheme by which these errors may be corrected.

6 pages, 4 figures, submitted to Phys. Rev. B

References in corpus (8)

• Density functional method for nonequilibrium electron transport
• Time-Dependent Partition-Free Approach in Resonant Tunneling Systems
• A first-principles approach to electrical transport in atomic-scale nanostructures
• Dynamical corrections to the DFT-LDA electron conductance in nanoscale systems
• Time-dependent quantum transport: an exact formulation based on TDDFT
• Electrostatic potential profiles of molecular conductors
• Maximum-entropy theory of steady-state quantum transport
• Many-body approach to infinite non-periodic systems: application to the surface of semi-infinite jellium

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• Modelling of inelastic effects in molecular electronics
• Genuine converging solution of self-consistent field equations for extended many-electron systems