Magnetoplasma excitations of two vertically coupled dots

A classical hydrodynamic approach is used to calculate the magnetoplasma excitations of two vertically coupled electron dots. The electrons are confined by different parabolic potentials in which case Kohn's theorem is no longer valid. The equilibrium density profiles of the electrons in both dots are calculated as function of the interdot distance. We find that for unequal confinements of the two dots the electron density in one of the dots becomes ring-like. The electron densities are then used to obtain the magnetoplasma frequencies. The oscillator strengths are calculated, and we find that other then the center of mass modes can be excited due to the electron-electron interactions.