Oscillator strengths for optical transitions near a cylindrical cavity

Abstract

The energy spectrum of a single electron confined near a cylindrical cavity is first determined within the effective-mass approximation as a function of the parallel applied magnetic field. The overall confinement of the electron is by the magnetic field and by the potential of the heterostructure, assumed to be parabolic in the radial distance from the surface of the hole. The single-electron energy spectrum depends in a critical way on the value of the hole radius. The oscillator strengths for optical transitions involving the lowest-order energy subbands are then evaluated within the dipole approximation. The radiation field is taken as that of circularly polarized light incident along the axis of the cavity. In the dipole approximation and for this polarization, the only allowed transitions are those for which the relevant subbands are characterized by the azimuthal quantum numbers which differ by unity. Strong transitions are predicted between the subbands whose energy gaps open-up as a result of increasing confinement of the electron by the magnetic field.