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 language | English (US) |
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Pages (from-to) | 578-581 |
Number of pages | 4 |
Journal | Physica Status Solidi (C) Current Topics in Solid State Physics |
Volume | 4 |
Issue number | 2 |
DOIs | |
State | Published - 2007 |
Event | International Conference on Superlattices, Nano-structures and Nano-devices, ICSNN-2006 - Istanbul, Turkey Duration: Jul 30 2006 → Aug 4 2006 |
ASJC Scopus subject areas
- Condensed Matter Physics