Light confinement in a quantum dot

The phenomenon of light confinement in an isolated quantum dot, originating from the electromagnetic wave diffraction at the dot boundary, is discussed. It has been shown that at a certain condition the quantum dot behaves as a microcavity whose eigenmodes manifest themselves as additional, geometrical, resonances in the quantum dot electromagnetic response. The effect of induced magnetization of the quantum dot is predicted and illustrated by the example of magnetic resonances in spherical quantum dots. The radiative lifetime for a spherical quantum dot has been evaluated and a correlation has been discussed between radiative lifetimes in quantum dots and quantum wells.