Deformed cyclotronic orbits for shallow impurities in cylindrical quantum well wires

The purpose this work is to study the behavior of the binding energy for do nor shallow impurities in cylindrical quantum well wires at different radia l positions. The model considers a finite confinement potential and the pre sence of a magnetic field applied parallel to the wire axis. Our results sh ow that cyclotronic orbits are deformed as the impurity moves along the rad ial position, due to a competition between geometrical and magnetic confine ment. As a result of this broken symmetry, we observe an induced change, fr om diamagnetic to paramagnetic, in the character of the ground-state of the system. These quantum mechanical calculations have been performed by using a variational method within the effective-mass theory. (C) 1999 Published by Elsevier Science Ltd. All rights reserved.