Electronic states and nonlinear optical properties of a two-dimensional hexagonal quantum dot: Effects of impurity, geometrical size and confinement potential

In the present work, the linear and the third-order nonlinear optical absorption coefficients as well as refractive-index changes in a two-dimensional hexagonal quantum dot with the presence of an impurity are calculated. A matrix diagonalization method is used to calculate energy levels and corresponding wave functions in the effective-mass approximation. Also, by means of the compact-density matrix approach the linear and nonlinear optical absorption coefficients and refractive-index changes are calculated. The effects of the impurity, the size of the dot and the confinement potential on energy eigenvalues, optical absorption coefficients and refractive-index changes are investigated. It is found that the energy eigenvalues, absorption coefficients and refractive-index changes are strongly dependent on the dot size, the confinement potential and the effects produced by the impurity.