EXCITATION SPECTRUM OF QUANTUM-DOT IN STRONG MAGNETIC-FIELD

Microscopic theory of collective excitations of a quantum dot in a str ong magnetic field is proposed. A complete analysis of diagrams in the perturbation theory over the Coulomb interaction is performed. The sp ectrum of low-lying excitations is calculated for the case of a parabo lic quantum dot. It is shown to consist of three terms: single-particl e drift, magnetoplasma and exciton ones, with the exciton term dominat ing the magnetoplasma one. In the framework of the semi-classical appr oach, the case of a non-parabolic quantum dot is also discussed. The e xperimental manifestations of the effects under investigation are disc ussed.