Electron coupling in weakly and strongly coupled quantum point contacts

K. J. Friedland, T. Saku, Yoshiro Hirayama, K. H. Ploog

Research output: Contribution to journalArticlepeer-review

10 Citations (Scopus)

Abstract

We present electron transport investigations in coupled double quantum point contacts defined by a split gate on the top of a novel narrow-barrier double-quantum-well structure. Using different barrier heights between the wells, we fabricated devices with strong and weak coupling. Mixing of the wavefunctions occurs in the strong coupling device with an (Al, Ga)As barrier. We are able to determine the sublevel spacing energy as well as the symmetric-antisymmetric sublevel splitting energy ΔSAS. In-plane magnetic fields change the energy diagram of the double quantum point contact giving rise to new crossing and anticrossing states. For the weak coupling device with an AlAs barrier, we find an intriguing reduction of the height of the conductance steps due to the imperfect coupling between 1D subbands and the two-dimensional reservoir. This allows us to quantitatively estimate the coupling.

Original languageEnglish
Pages (from-to)144-148
Number of pages5
JournalPhysica E: Low-Dimensional Systems and Nanostructures
Volume11
Issue number2-3
DOIs
Publication statusPublished - 2001 Jan 1
Externally publishedYes

Keywords

  • Ballistic electronic transport
  • Low-dimensional structures
  • Tunnelling
  • Wave function mixing

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Atomic and Molecular Physics, and Optics
  • Condensed Matter Physics

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