Abstract:
Optical absorptions of the low-lying states with higher angular momenta of the D– system in a spherical quantum dot (QD) with the Gaussian potential are studied by using the matrix diagonalisation method and the compact density-matrix approach. The linear, nonlinear third-order and total optical absorption coefficients are calculated for the 1P– → 1D+ and 1D+ → 1F– transitions. Numerical results for GaAs/Ga1-xAlxAs QDs are presented. The calculated results show that with increasing quantum numbers describing the angular momenta of transitions the optical absorption peaks shift towards lower energies and their intensities increase.
Keywords:quantum dot, negative-donor system, excited states.