Szczegóły publikacji
Opis bibliograficzny
Manipulation of two-electron states by the electric field in stacked self-assembled dots / M. P. NOWAK, B. SZAFRAN, F. M. Peeters // Journal of Physics : Condensed Matter ; ISSN 0953-8984 . — 2008 — vol. 20 iss. 39, s. 395225-1–395225-14. — Bibliogr. s. 395225-13–395225-14, Abstr.
Autorzy (3)
- AGHNowak Michał Piotr
- AGHSzafran Bartłomiej
- Peeters François Maria
Dane bibliometryczne
| ID BaDAP | 42517 |
|---|---|
| Data dodania do BaDAP | 2009-01-12 |
| Tekst źródłowy | URL |
| DOI | 10.1088/0953-8984/20/39/395225 |
| Rok publikacji | 2008 |
| Typ publikacji | artykuł w czasopiśmie |
| Otwarty dostęp |  |
| Czasopismo/seria | Journal of Physics-Condensed Matter |
Abstract
A pair of electrons in vertically stacked self-assembled quantum dots is studied and the singlet-triplet energy splitting is calculated in an external electric field using the configuration-interaction method. We show that for double quantum dots the dependence of the singlet energy levels on the electric field involves multiple avoided crossings of three energy levels. The exchange interaction, i.e., the energy difference of the lowest triplet and lowest singlet states, can be tuned by an electric field in a wide range of several tens ofmeV. For electric fields exceeding a threshold value the exchange interaction becomes a linear function of the field when the two electrons in the singlet state start to occupy the same dot. We also consider non-symmetric confinement, non-perfectly aligned dots, in horizontal as well as vertical field orientation. In a stack of three vertically coupled dots the depth of the confinement in the central dot can be used to enhance the exchange interaction. For a deeper central dot the dependence of the exchange interaction on the electric field is anomalous - it initially decreases when the field is applied in both directions parallel and antiparallel to the axis of the stack. Such a behavior is never observed for a pair of quantum dots.
