MANY-ELECTRON GROUND-STATES IN ANISOTROPIC PARABOLIC QUANTUM DOTS

The many-electron ground states in anisotropic parabolic quantum dots with the cylindrical symmetry are investigated by means of an unrestri cted Hartree-Fock method. The calculated ground state of a large quant um dot is completely spin polarized up to 12 electrons, while the spin configuration of a small quantum dot obeys the Hund rule. The chemica l potential and the differential capacitance of quantum dots are calcu lated as well. The capacitance shouts the characteristic oscillation w ith an electron number caused by the shell structures of single-electr on energy levels which are determined self-consistently with the spin configuration of the many-electron ground state. On the differential c apacitance, the effect of the vertical extent of a dot is also studied . It becomes larger as the lateral extent of a quantum dot decreases, maintaining the same ratio to the vertical extent. Further, the effect in a small dot becomes especially enhanced at the special number of e lectrons, N = 2,5,10,17,..., due to the shell structure. The excited s tates, which have different quantum numbers from the ground state, are also studied.