Engineering exchange coupling in double elliptic quantum dots

Lingxiao Zhang, Dmitriy V. Melnikov, Jean Pierre Leburton

Research output: Contribution to journalArticlepeer-review

Abstract

Coupled elliptic quantum dots with different aspect ratios containing up to two electrons are studied using a model confinement potential in the presence of magnetic fields. Single and two-particle Schrödinger equations are solved using numerical exact diagonolization to obtain the exchange energy and chemical potentials. As the ratio between the confinement strengths in directions perpendicular and parallel to the coupling direction of the double dots increases, the exchange energy at zero magnetic field increases, while the magnetic field of the singlet-triplet transition decreases. By investigating the charge stability diagram, we find interdot quantum mechanical coupling increases with the dot aspect ratio, whereas the electrostatic coupling between the two dots remains nearly constant. With increasing interdot detuning, the absolute value of the exchange energy increases superlinearly followed by saturation. This behavior is attributed to the electron density differences between the singlet and triplet states in the assymetric QD systems.

Original languageEnglish (US)
Pages (from-to)250-254
Number of pages5
JournalIEEE Transactions on Nanotechnology
Volume6
Issue number2
DOIs
StatePublished - Mar 2007

Keywords

  • Exact diagonalization
  • Exchange energy
  • Quantum dots (QDs)
  • Simulation

ASJC Scopus subject areas

  • Engineering(all)
  • Hardware and Architecture

Fingerprint Dive into the research topics of 'Engineering exchange coupling in double elliptic quantum dots'. Together they form a unique fingerprint.

Cite this