EIGENSTATES AND FINE-STRUCTURE OF A HYDROGENIC IMPURITY IN A SPHERICAL QUANTUM-DOT

Citation
Cc. Yang et al., EIGENSTATES AND FINE-STRUCTURE OF A HYDROGENIC IMPURITY IN A SPHERICAL QUANTUM-DOT, Physical review. B, Condensed matter, 58(4), 1998, pp. 1954-1961
Citations number
14
Categorie Soggetti
Physics, Condensed Matter
ISSN journal
01631829
Volume
58
Issue
4
Year of publication
1998
Pages
1954 - 1961
Database
ISI
SICI code
0163-1829(1998)58:4<1954:EAFOAH>2.0.ZU;2-9
Abstract
The fine structure of the energy levels for a hydrogenic impurity loca ted in the center of a spherical quantum dot is calculated using a sim pler exact solution for the potential well. The results reveal that wh en the dot radius approaches zero, the eigenenergies are just like a f ree-space hydrogenic atom. When the doe radius is large enough, then t he eigenenergies approach a free-space hydrogenic atom but are shifted by the confining potential. Also we find that the radial expectation values will be equal to a free-space hydrogenic atom, when the dot rad ius is extremely small and extremely large. Between these two situatio ns, the radial expectation values are smaller than those of a free spa ce because of the pressing of the confining potential. Not every dot r adius influences the eigenenergy to the same degree. It is decided by the bumps of the electron's wave function and the place of the potenti al well's margin. When the margin of the well begins to push the bumps of the wave then the eigenenergy will increase more quickly. Because of the changing of the electron distribution probability, the degenera cy of the different I value in a free-space hydrogenic atom is removed by the confining potential. The total-energy shifts of the fine struc ture of the impurity could be six times larger than the total energy s hifts of a free-space atom.