Theory of excitonic artificial atoms: InGaAs/GaAs quantum dots in strong magnetic fields

Abstract

We develop a theory of excitonic artificial atoms in strong magnetic fields. The excitonic atoms are formed by N electrons and holes confined in a quantum dot. The single-particle levels are described by the Fock-Darwin spectrum in a magnetic field. The magnetic field induces crossing of energy levels and allows us to engineer degenerate shells. We apply exact diagonalization techniques to calculate the magnetic-field evolution of the ground state of the N-electron-hole complex and its emission spectra. We focus on degenerate shells and show that excitons condense into correlated states due to hidden symmetry. We relate the Fock-Darwin spectrum, hidden symmetries, and direct and exchange interaction among particles to the emission spectra as a function of number of electron-hole pairs (excitation power) and magnetic field.