Abstract
Quantum dots (QDs) realized by etching or gate structures in a two-dimensional electron system may, under realistic conditions, contain an impurity atom which causes deviations of the electron structure from the ideal case. We have performed ground-state calculations for circular disk-like QDs with a parabolic confinement potential and a repulsive off-center impurity. Besides the distance of the impurity from the dot center we can vary its strength using a Coulomb potential for its shape. The essential effect of the off-center impurity is the breaking of the axial symmetry with the consequence of removing degeneracies in the single-particle spectrum which is related to shell and spin phenomena. We quantify these effects in the ground-state energy and the spin densities by applying spin-density functional theory (SDFT) in the local spin density approximation (LSDA).
Original language | English |
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Pages (from-to) | 675-679 |
Number of pages | 5 |
Journal | Physica Status Solidi (B) Basic Research |
Volume | 224 |
Issue number | 3 |
DOIs | |
State | Published - Apr 2001 |
Externally published | Yes |