Optical properties of an exciton in a two-dimensional quantum ring with an applied magnetic field

We study theoretically the optical properties of an exciton in a two-dimensional quantum ring both including harmonic dot and antidot potentials in the presence of a strong magnetic field. Calculations are made by using the perturbation method and the compact density-matrix approach within the effective-mass approximation. Based on the computed energies and wave functions, the linear, third-order nonlinear and total optical absorption coefficients as well as the refractive index changes have been examined. The results show that the optical properties of an exciton in a two-dimensional ring both including harmonic dot and antidot potentials are strongly affected by the zero point of the pseudoharmonic potential, the chemical potential of the electron gas and the applied magnetic field. The larger optical nonlinearity will be obtained by varying the zero point of the pseudoharmonic potential compared to the chemical potential of electron gas and the applied magnetic field.