In this study, we have investigated the influence of an external electric field on the electronic properties of the ground and excited states and studied the linear and the third-order nonlinear optical properties (i.e., absorption coefficients and refractive indices) in a spherical semiconductor quantum dot of a parabolic confinement with an on-center shallow hydrogenic impurity. In the calculations, a variational procedure was employed within the effective-mass approximation. We found that the binding energies of the ground and excited states, the absorption coefficients, and the refractive index changes of 0s-1p and 1p-2d transitions depend on the applied electric field. The results show that the existence of the electric field has great influence on the optical absorption coefficients and the refractive index changes. Also, we have found that the magnitudes of the absorption coefficient and the refractive index change of the spherical quantum dot increase for transitions between higher levels.

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Dynamic phase diagrams are calculated, within a mean-field approach, for the kinetic metamagnetic spin-3/2 Blume -Capel model in the presence of a time-dependent oscillating external magnetic field using Glauber-type stochastic dynamics and six fundamental types of phase diagrams are found in the reduced temperature (T) and magnetic-field amplitude parameter (h) plane. The phase diagrams exhibit one, two or three dynamic tricritical points, and besides the paramagnetic (P), the antiferromagnetic-3/2 (AF 3/2 ), the antiferromagnetic-1/2 (AF 1/2 ) phases, three coexistence phase regions, namely AF 3/2 + P, AF 1/2 + P, AF 3/2 + AF 1/2 , exist depending upon the interaction parameters. The dynamic phase boundaries between the P and AF 3/2 phases are always second-order lines, but between the P and AF 1/2 phases are second-or/and first-order lines. All other dynamic phase boundaries among the disordered, ordered phases and coexistence phase regions are first-order lines. We have investigated the influence of the crystal field interaction (D) and we obtain five different phase diagram topologies in (d, T ) plane, / . d D = ¢ J We have also studied the influence of the frequency on the phase boundaries as well as the dynamic tricritical point and found that the topologies of the phase diagrams slightly change.