MICROSCOPIC THEORY OF EXCITATIONS OF A QUANTUM-DOT IN STRONG MAGNETIC-FIELD

The excitation spectrum of a parabolic quantum dot in quantizing magne tic field is investigated in terms of the diagrammatic technique. The case of weak confining potential is considered. A full classification of diagrams is presented. It occurs that the confining potential drama tically alters the excitation nature. As for the lowest branch of the spectrum, the frequencies are essentially the sums of three terms: sin gle-particle drift, magnetoplasmon, and exciton contributions. The exc iton term dominates the magnetoplasmon one.