EFFECTS OF BAND-STRUCTURE AND SPIN IN QUANTUM DOTS

Band structure and spin can modify the simple two-mode far-infrared spectra of quantum dots. In our investigation of these effects we start from a k.p Hamiltonian for the conduction, valence, and spin-orbit split-off bands, with potentials for subband formation and harmonic lateral confinement. Taking into account the nonparabolicity of the conduction band and spin-orbit coupling due to the confining potentials, we calculate the dipole excitation spectra of quantum dots on InSb with one and two electrons. Spin-orbit coupling leads to a level anticrossing in the omega- mode and nonparabolicity modifies the omega+ mode demonstrating violation of Kohn's theorem.