Structure dependent third order nonlinear susceptibility in the presence of impurity and magnetic field in CdS/ZnS core/shell quantum dot

Abstract

Third order nonlinear optical susceptibility due to intersubband optical transition of an electron confined in a CdS/ZnS core-shell quantum dot is investigated for various sizes of core and shell radii in the presence of magnetic field. It is computed by employing the variational approach within the effective mass approximation and the two level density matrix method is applied to obtain the transition energy between two levels. The dependence on third order susceptibility of the incident light is investigated. The results show that the third order nonlinear optical susceptibility is blueshifted with the reduction of inner core radius for a constant outer radius and the same trend is observed with the decreasing outer shell radius. The resonant wavelength and the peak of third order susceptibility will be managed by the control over the structure of core-shell materials and the external perturbation.