Quantum point contact potential curvature under correlated disorder potentials

T. Aono, M. Takahashi, M. H. Fauzi, Y. Hirayama

Research output: Contribution to journalArticlepeer-review

Abstract

We theoretically investigate the curvature of the confinement potential in quantum point contacts (QPCs) under a background disorder potential with Gaussian correlation functions using a noninteracting one-dimensional tight-binding model. The curvature of the potential is evaluated from the gate voltage dependence of the conductance, and the statistical average of the fitting curvature is calculated. The fitting curvature is insensitive to the original QPC confinement curvature when the characteristic length of the QPC potential is larger than the characteristic length of the disorder. In addition, the fitting curvature can be enhanced as the QPC curvature is decreased. Accidental double barrier potential formation on the top of the QPC induces enhancement of the fitting curvature. Finite-temperature effects under the disorder potential are also discussed. Similar results hold in a two-dimensional QPC tight-binding model.

Original languageEnglish
Article number045305
JournalPhysical Review B
Volume102
Issue number4
DOIs
Publication statusPublished - 2020 Jul 15

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics

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