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Technical Report CMS-TR-20080917


Title Impurity effects on the electronic structure of square quantum dots: A full configuration- interaction study
Author/s Bhalchandra S. Pujari
Centre for Modeling and Simulation,Savitribai Phule Pune University, Pune 411 007 India


Kavita Joshi
Centre for Modeling and Simulation,Savitribai Phule Pune University, Pune 411 007 India


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


S. A. Blundell
Service de Physique Statistique, Magnétisme et Supraconductivité, INAC, CEA-Grenoble/DSM, 17 rue des Martyrs, F-38054 Grenoble Cedex 9, France
Abstract We perform a full configuration-interaction study on a square quantum dot containing several electrons in the presence of an attractive impurity. The magnetic ordering in the dot is analyzed using appropriate pair- correlation functions. We find that a change in the size of the quantum dot can change the nature of the impurity from nonmagnetic to magnetic. In the low-density regime, the impurity traps one electron and the magnetic moment on the localized peaks outside the impurity fluctuates from negative to positive going through zero as a function of number of electrons. We also observe that the impurity changes the charge densities of excited states of two-electron quantum dot significantly, which in the absence of the impurity are almost similar. Our study also shows that in the strongly correlated regime the configuration-interaction ap- proach yields ~20% more localization than density-functional theory. It has also been observed that only a small fraction of the total number of Slater determinants are required to produce ϳ99% of the converged charge density.
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Citing This Document Bhalchandra S. Pujari, Kavita Joshi, D. G. Kanhere, and S. A. Blundell , Impurity effects on the electronic structure of square quantum dots: A full configuration- interaction study . Technical Report CMS-TR-20080917 of the Centre for Modeling and Simulation, Savitribai Phule Pune University, Pune 411007, India (2008); available at http://cms.unipune.ernet.in/reports/.
Notes, Published Reference, Etc. Published as Physical Review B 78, 125414 (2008)
Contact bspujari AT cms.unipune.ernet.in
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