Linear and nonlinear optical properties of semiconductor nanorings with magnetic field and disorder - Influence on excitons and biexcitons

Linear and nonlinear optical absorption spectra are studied theoretically f or semiconductor nanorings penetrated by a magnetic field. Due to the Ahara nov-Bohm effect the spectral Position as well as the oscillator strength of the exciton change periodically as function of the magnetic flux enclosed by the ring. In the nonlinear differential absorption spectra it is found t hat the magnetic field strongly modifies Coulomb many-body correlations. In particular, the magnetic-field-induced increase of the exciton binding ene rgy is accompanied by a decrease of the biexciton binding energy. The persi stence of these effects in the presence of energetic disorder is analyzed.