Singlet-triplet ground-state instability in square quantum dot

Yuki Negishi, Masamu Ishizuki*, Atsushi Tsubaki, Kyozaburo Takeda, Yusuke Asari, Takahisa Ohno

*この研究の対応する著者

研究成果: Conference contribution

抄録

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 D 4h. This ground-state triplet is also found even in the deformed SQD (D 2h) 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 D 4h. The strong electron-localization causes the destabilization in the orbital (kinetic) energies, and produces this characteristic "anti-Hund" state.

本文言語English
ホスト出版物のタイトルPhysics of Semiconductors - 30th International Conference on the Physics of Semiconductors, ICPS-30
ページ497-498
ページ数2
DOI
出版ステータスPublished - 2011 12月 1
イベント30th International Conference on the Physics of Semiconductors, ICPS-30 - Seoul, Korea, Republic of
継続期間: 2010 7月 252010 7月 30

出版物シリーズ

名前AIP Conference Proceedings
1399
ISSN(印刷版)0094-243X
ISSN(電子版)1551-7616

Conference

Conference30th International Conference on the Physics of Semiconductors, ICPS-30
国/地域Korea, Republic of
CitySeoul
Period10/7/2510/7/30

ASJC Scopus subject areas

  • 物理学および天文学(全般)

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