THE EFFECT OF A LONGITUDINAL MAGNETIC-FIELD ON ELECTRONIC INTERSUBBAND TRANSITIONS IN ASYMMETRIC HETEROSTRUCTURES

Infrared absorption spectra are calculated for electronic intersubband transitions in asymmetric heterostructures subjected to a longitudina l magnetic field. The systems discussed include a single quantum well in a transverse electric field, a ''stepped'' quantum well, and a doub le well with tunnel-coupled excited levels. The longitudinal magnetic field causes collisionless broadening of the absorption peaks (because the effect of the magnetic field on the dispersion law of an electron ic state varies from state to state, which modifies the transitions be tween them) and absorption of normally incident light (due to changes in the selection rules). (C) 1997 American Institute of Physics.