ELECTRON CORRELATIONS IN QUANTUM RING AND DOT SYSTEMS

A model for a quantum ring in magnetic fields is introduced where various electronic properties viz., the single- and many-electron energy spectrum, magnetization (persistent current) and the dipole-allowed absorption energies can be studied very accurately. The impurity potential lifts the degeneracies in the energy spectrum and the persistent current is then reduced from the impurity-free value. The effect of the Coulomb interaction on the persistent current is, however, insignificant. The dipole-allowed absorption energies in a quantum ring are presented. Similar studies for a quantum dot with a Gaussian impurity in the middle reveal quite rich structures in the absorption spectrum.