Xh. Wang et al., COUPLING BETWEEN NORMAL AND LATERAL DEGREES OF FREEDOM OF AN ELECTRONIN QUANTUM-WELLS AND SUPERLATTICES AT ZERO AND FINITE MAGNETIC-FIELDS, Physical review. B, Condensed matter, 56(15), 1997, pp. 9224-9227
We present the effective-barrier-height method to investigate the effe
cts of coupling between normal and lateral degrees of freedom of an el
ectron 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 nume
rical calculations for GaAs/AlxGa1-xAs materials show that the couplin
g effect leads not only to the shift of the sublevels in QW's and subb
and, in SL's toward the well bottom with increasing k(xy) or n, but al
so 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 var
iation of the shift of levels in QW's with the well width and found th
at this coupling effect becomes more striking in thin QW's.