| Autor: |
Yuki Negishi, Masamu Ishizuki, Atsushi Tsubaki, Kyozaburo Takeda, Yusuke Asari, Takahisa Ohno, Jisoon Ihm, Hyeonsik Cheong |
| Rok vydání: |
2011 |
| Předmět: |
|
| Zdroj: |
AIP Conference Proceedings. |
| ISSN: |
0094-243X |
| DOI: |
10.1063/1.3666471 |
| Popis: |
We theoretically study the spin multiplicity in the ground state of the square quantum dot (SQD) including four electrons, and discuss a possibility of the singlet‐triplet (S/T) instability in the quantum system. As predicted by Hund's rule, the ground‐state triplet appears when the DQD has a point group symmetry of D4h. This ground‐state triplet is also found even in the deformed SQD (D2h) if the confinement length L is elongated. Consequently, the S/T instability is expected along these boundary lines. It is also worthwhile to notice that the present DFT as well as UHF calculation predicts the spin‐singlet ground‐state when the inter‐electron interaction is strengthened (larger L) even though the SQD maintains its geometrical form of D4h. The strong electron‐localization causes the destabilization in the orbital (kinetic) energies, and produces this characteristic “anti‐Hund” state. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
|
