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Technical Report CMS-TR-20070824


Title Electronic structure of many-electron square-well quantum dots with and without an attractive impurity: Spin-density-functional theory
Author/s Bhalchandra Pujari
Centre for Modeling and Simulation, Savitribai Phule Pune University, Pune 411 007 India


Kavita Joshi
Department of Physics, Savitribai Phule Pune University, Ganeshkhind, Pune 411 007, India


D. G. Kanhere
Department of Physics, Savitribai Phule Pune University, Ganeshkhind, Pune 411 007, India


S. A. Blundell
Département de Recherche Fondamentale sur la Matière Condensée, CEA-Grenoble/DSM, 17 rue des Martyrs,F-38054 Grenoble Cedex 9, France
Abstract The electronic structure of many-electron square-well quantum dots with and without an attractive impurity has been investigated within the spin-density-functional theory. We consider various sizes of quantum dots with the number of electrons varying from 2 to 20. We observe the emergence of localized Wigner-molecule- like behavior along with the wall-like feature in the charge density. However, unlike the parabolic quantum dots, we do not observe the analog of concentric rings. We also observe the typical broken symmetry configu- rations noted in earlier reports for quantum dots. The impurity induces the localized magnetic moment which, in many cases, generates the spin-polarized configurations with the antiferromagnetic coupling. An examina- tion of the magnetic states indicates that the presence of impurity may change the ground state of quantum dot from magnetic to nonmagnetic and vice versa. We also observe that the localized charge at the center sharpens the walls.
Keywords
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Citing This Document Bhalchandra Pujari, Kavita Joshi, D. G. Kanhere, and S. A. Blundell , Electronic structure of many-electron square-well quantum dots with and without an attractive impurity: Spin-density-functional theory . Technical Report CMS-TR-20070824 of the Centre for Modeling and Simulation, Savitribai Phule Pune University, Pune 411007, India (2007); available at http://cms.unipune.ernet.in/reports/.
Notes, Published Reference, Etc. Published as Physical Review B 76, 085340 (2007)
Contact bspujari AT cms.unipune.ernet.in
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