Far-infrared absorption of self-assembled semiconductor rings

We report a theoretical description of far-infrared spectroscopy experiments on self-assembled quantum rings in a magnetic field [A. Lorke et al., Phys. Rev. Lett. 84, 2223 (2000)] which, for the first time, accounts for the full set of experimental resonances. In our calculations we use a 3D effective-mass model with a realistic finite step-like confinement potential, including strain and Coulomb effects. We assume a bimodal distribution of ring sizes.