Effects of applied electric and magnetic fields on a donor impurity in laterally coupled quantum dots

A theoretical description of the electronic structure, optical spectrum and binding energy of a hydrogenic impurity in laterally coupled quantum discs, under applied electric and magnetic fields, is given within the framework of the effective-mass approach. Calculations are performed using the envelope-function formalism and a variational procedure, with the electric field applied in the coupling direction, the magnetic field along the growth direction, and the impurity at the center of the heterostructure. The results indicate that the anisotropy of the laterally coupled confinement potential leads to interesting relative extrema and anticrossings in the energy spectra, and that the infrared absorption spectrum is sensitive to the type of polarization and magnitude of external fields.