Charged magnetoexcitons in parabolic quantum dots

We study a charged exciton in two-dimensional parabolic quantum dots containing N $(0\mathrm{}<~N<~12)$ electrons in a magnetic field by using an unrestricted Hartree-Fock method, in both strong and weak confinement regimes for electrons and holes. In the case of strong confinement, our results on absorption intensities and shifts in energies of interband transitions compare well with recent experiments by Warburton et al. [Phys. Rev. Lett. 79, 5282 (1997)]. In the weak confinement regime, the calculated absorption spectra show new features reflecting the transition of the many-electron ground state, both in the absence and in the presence of external magnetic fields. The dependence of the intensity and the energy shift of transitions on the electron occupation and on magnetic fields is studied. The fine structure of interband absorption spectra due to both magnetic fields and the asymmetry between electrons and holes and the effects of polarization of lights are predicted, which can be detected in experiments on single dots.