Intradonor absorption spectra under external fields in quantum wells

The effects of magnetic and electric fields on the infrared-absorption properties associated to transitions between the Is-like and 2p(+/-)-, 3p(+/-)-, and 4p(+/-)-like excited states of hydrogenic donors in GaAs-Ga1-xAlxAs quantum wells are studied. The magnetic and electric fields are applied along the growth direction of the heterostructure, and donor envelope wave functions and energies are obtained within a variational procedure in the effective-mass approximation. Calculations for the intradonor transition strengths for x-polarized radiation and absorption coefficients are performed for finite-barrier potentials and as functions of applied magnetic and electric fields and quantum-well thicknesses. A discussion of a sum rule associated to donor transitions in quantum wells is presented. Theoretical results for the absorption spectra are in good agreement with available infrared-magnetospectroscopy measurements on doped quantums wells.5315101601016