COUPLING BETWEEN NORMAL AND LATERAL DEGREES OF FREEDOM OF AN ELECTRON IN QUANTUM WELLS AND SUPERLATTICES AT ZERO AND FINITE MAGNETIC FIELDS

摘要

We present the effective-barrier-height method to investigate the effects of coupling between normal and lateral degrees of freedom of an electron in the parabolic conduction-band approach. This is performed on electronic states in quantum wells (QW's) and superlattices (SL's) at zero and finite magnetic fields perpendicular to interfaces. The numerical calculations for GaAs/AlxGa1-xAs materials show that the coupling effect leads not only to the shift of the sublevels in QW's and subband, in SL's toward the well bottom with increasing k(xy) or n, but also to the disappearance of high excited states close to the top of the barrier when k(xy) or n exceeds a certain value owing to the the fast lowering of the effective-barrier height. We also investigate the variation of the shift of levels in QW's with the well width and found that this coupling effect becomes more striking in thin QW's. [References: 11]