Asymptotic self-consistency in quantum transport calculations

H Mera, P Bokes, R W Godby

Research output: Contribution to journalArticlepeer-review

Abstract

Ab initio simulations of quantum transport commonly focus on a central region which is considered to be connected to infinite 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 Delta phi is effectively being approximated by the difference between electrochemical potentials Delta mu, and that this approximation is incompatible with asymptotic charge neutrality. In a test calculation for a simple metal-vacuum-metal junction, we find significant errors in the nonequilibrium properties calculated with this approximation, in the limit of small vacuum gaps. We provide a scheme by which these errors may be corrected.

Original languageEnglish
Article number085311
Pages (from-to)-
Number of pages6
JournalPhysical Review B
Volume72
Issue number8
DOIs
Publication statusPublished - Aug 2005

Bibliographical note

© 2005 American Physical Society. This is an author produced version of a paper published in Physical Review B. Uploaded in accordance with the publisher's self archiving policy.

Keywords

  • VACUUM-METAL JUNCTIONS
  • ELECTRONIC-STRUCTURE
  • BARRIER
  • FORMULA
  • FIELD

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