Effects of external electric and magnetic fields on the linear and nonlinear optical properties of InAs cylindrical quantum dot with modified Pöschl-Teller and Morse confinement potentials

Abstract

The theoretical investigation of linear and third-order nonlinear absorption coefficients and refractive index changes in the cylindrical quantum dot with two models of confinement potentials in axial direction, namely, modified Pöschl-Teller and Morse potentials, and parabolic potential in radial direction, have been considered in the presence of external electric and magnetic fields. The selection rules for intraband transitions have been obtained for both potentials in the presence and absence of external fields. The behavior of linear, nonlinear and total absorption spectra have been observed for different values of temperatures for both potentials taking into account electron population on energy levels. The effect of change in the direction of electric field on the absorption spectra have been investigated, and the asymmetric and symmetric characters of these potentials manifest themselves differently: the peak positions of absorption lines for Morse potential undergo blue and red shifts compared to the case when the external electric field is absent, while for the case of modified Pöschl-Teller potential the absorption lines have only red shift. The same dependencies have been obtained for refractive index changes for both potentials. The second and third harmonic generation coefficients as a function of the photon energy have been plotted both in the absence and presence of external fields.