Many-electron artificial atoms

Artificial atoms, i.e., systems of excess electrons confined in semiconduct or quantum dots, are studied by the unrestricted Hartree-Fock method. We co nsider a spherical quantum dot embedded in an insulating matrix and assume a confinement potential in a form of spherical potential well of radius R a nd depth V-0. The calculations have been performed for few- and many-electr on artificial atoms with the number of electrons from 1 to 20. We have show n that bound many-electron states of atomlike properties are created in qua ntum dots if the values of R and V-0 are sufficiently large. The critical v alues of R and V-0 for the binding of N electrons in the quantum dots have been determined. We have found that the subsequent shells of the artificial atoms are filled by electrons according to the Hund rule. The characterist ic behavior resulting from the full and half-filling of the shells is clear ly visible in the dependence on the number of electrons of the calculated c hemical potential, addition energy, and electric capacitance of the quantum dots. The present results have been compared with those of the classical T homson model of atoms and applied to the quantum dots made of Si and GaAs. [S0163-1829(99)00320-3].