Single-particle state mixing and Coulomb localization in two-electron realistic coupled quantum dots

Dmitriy V. Melnikov, Jean-Pierre Leburton

Research output: Contribution to journalConference article

Abstract

The exchange coupling in a realistic double quantum dot system is computed as a function of the gate confinement and magnetic field using a hybrid multiscale approach where the many-body Schrödinger equation is solved exactly within the full quantum dot device environment. It is found that at zero magnetic field the exchange energy varies from meV to sub-μeV value as the confinement gate biases (tunneling barrier) are changed and the system is driven from a single quantum dot to two coupled quantum dots. At the same time the magnetic field of the singlet-triplet transition is weakly affected by the changes and remains at about 1 T in the same range of the gate biases. The small values of the exchange coupling in this structure are attributed to the large inter-electron separation arising when the Coulomb repulsion dominates tunneling.

Original languageEnglish (US)
Pages (from-to)578-581
Number of pages4
JournalPhysica Status Solidi (C) Current Topics in Solid State Physics
Volume4
Issue number2
DOIs
StatePublished - Dec 1 2007
EventInternational Conference on Superlattices, Nano-structures and Nano-devices, ICSNN-2006 - Istanbul, Turkey
Duration: Jul 30 2006Aug 4 2006

ASJC Scopus subject areas

  • Condensed Matter Physics

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