Optical nonlinearities associated to applied electric fields in parabolic two-dimensional quantum rings

The linear and nonlinear optical absorption as well as the linear and nonlinear corrections to the refractive index are calculated in a disc shaped quantum dot under the effect of an external magnetic field and parabolic and inverse square confining potentials. The exact solutions for the two-dimensional motion of the conduction band electrons are used as the basis for a perturbation-theory treatment of the effect of a static applied electric field. In general terms, the variation of one of the different potential energy parameters - for a fixed configuration of the remaining ones - leads to either blueshifts or redshifts of the resonant peaks as well as to distinct rates of change for their amplitudes.