Impurity strength and impurity domain modulated frequency-dependent linear and second non-linear response properties of doped quantum dots

We explore the pattern of frequency-dependent linear and second non-linear optical responses of repulsive impurity doped quantum dots harmonically confined in two dimensions. The dopant impurity potential chosen assumes a Gaussian form and it is doped into an on-center location. The quantum dot is subject to a periodically oscillating external electric field. For some fixed values of transverse magnetic field strength (omega(c)) and harmonic confinement potential (omega(0)), the influence of impurity strength (V-0) and impurity domain (xi) on the diagonal components of the frequency-dependent linear (alpha(xx) and alpha(yy)) and second non-linear (gamma(xxxx) and gamma(yyyy)) responses of the dot are computed through a linear variational route. The investigations reveal that the optical responses undergo enhancement with increase in both V-0 and xi values. However, in the limitingly small dopant strength regime one observes a drop in the optical responses with increase in V-0. A time-average rate of energy transfer to the system is often invoked to support the findings. (C) 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim