Magnetic field effects on quantum ring excitons - art. no. 125302

We study the effect of magnetic field and geometric confinement on excitons confined to a quantum ring. We use analytical matrix elements of the Coulo mb interaction and diagonalize numerically the effective-mass Hamiltonian o f the problem. To explore the role of different boundary conditions, we inv estigate the quantum ring structure with a parabolic confinement potential, which allows the wave functions to be expressed in terms of center of mass and relative degrees of freedom of the exciton. On the other hand, wave fu nctions expressed in terms of Bessel functions for electron and hole are us ed for a hard-wall confinement potential. The binding energy and electron-h ole separation of the exciton are calculated as function of the width of th e ring and the strength of an external magnetic field. The linear optical s usceptibility as a function of magnetic fields is also discussed. We explor e the Coulomb electron-hole correlation and magnetic confinement for severa l ring width and size combinations. The Aharanov-Bohm oscillations of excit on characteristics predicted for one-dimensional rings are found to not be present in these finite-width systems.