CORRELATION-EFFECTS IN QUANTUM DOTS IN MAGNETIC-FIELDS

Tunneling rates into quantum dots in the presence of a magnetic field B are discussed by analyzing N-electron wave functions. Exact diagonalizations of the total Hamiltonian for up to 20 electrons are performed. When B is varied, transitions between uncorrelated states occur through strongly correlated states. Correlated states are responsible for the strong reduction of tunneling rates in the transition region. At high fields the lowest energy state within each subspace of given angular momentum is a magnetoexciton that can be generated by a novel set of operators. Correlation produces, once again, a reduction of tunneling rates. The spectral function presents damped oscillations as a function of the energy that can be described by the operators creating magnetoexcitons.