Photoluminescence in Cylindrical Quantum Well Wires in the Presence of Shallow Impurities and Magnetic Field

Abstract

A fundamental problem in third‐generation mobile systems is the adaptation of the channel allocation to the traffic volume variation. Traffic adaptation may be partly achieved by the following (aggregate channel allocation) problem: given the set of channels, the cell structure and the load to be accommodated in each cell within a certain time zone, find the optimal allocation of channels to cells subject to the restrictions arising from the minimum permissible distance of cells where the same channel can be used at the same time. In this paper the problem is optimally formulated and efficiently solved by a heuristic. In the sequel the performance of a combined channel management scheme that uses the above problem for handling major traffic variations and a distributed DCA scheme for handling local traffic variations is assessed. Finally, results are presented and some concluding remarks are made. © 1998 John Wiley & Sons, Ltd.

Binding Energy of Hydrogen-Like Impurities in a Thin Semiconductor Wire with Complicated Dispersion Law in a Magnetic Field

“…Extensive theoretical investigations on the behavior of shallow impurities in QWW in an external magnetic field have been carried out in [16][17][18][19].…”

“…Pé rez-Merchancano and Marques [16] have calculated the binding energy of a hydrogenic impurity localized on the axis of a cylindrical QWW in a uniform magnetic field applied parallel to the wire axis. Osorio et al [17] have theoretically treated the polarizability of a donor impurity in a GaAs QWW with a finite barrier potential in the presence of a magnetic field perpendicular to the wire axis.…”

“…The works [15][16][17][18][19] were carried out within the framework of the effective-mass approximation for the semiconductor QWW with parabolic bands. The calculation of the binding energy of the hydrogen-like impurity in magnetic field in a QWW of A 3 B 5 semiconductors with nonparabolic bands is of great interest.…”

The Binding Energies of Shallow Donor Impurities in GaAs–(Ga,Al)As Coaxial Quantum-Well Wires

“…Besides, there have been calculated the binding energies and the density of states of hydrogenic shallow donor impurities in quantumwell wires with rectangular cross sections under the influence of applied electric and magnetic fields [7,8]. The Slater type trial function with only one variational parameter has been used for QWW model with rectangular shape of the confinement potential [3,4,7,8] and an additional Gaussian-type factor has been introduced to take into account the effect of the external magnetic field [5,6]. It is clear that the type of the trial function depends strongly on the confinement potential shape and in general case it is impossible to choose the best of it a priori.…”

The Binding Energies of Shallow Donor Impurities in GaAs-(Ga,Al)As Coaxial Quantum-Well Wires

“…Besides, there have been calculated the binding energies and the density of states of hydrogenic shallow donor impurities in quantumwell wires with rectangular cross sections under the influence of applied electric and magnetic fields [7,8]. The Slater type trial function with only one variational parameter has been used for QWW model with rectangular shape of the confinement potential [3,4,7,8] and an additional Gaussian-type factor has been introduced to take into account the effect of the external magnetic field [5,6]. It is clear that the type of the trial function depends strongly on the confinement potential shape and in general case it is impossible to choose the best of it a priori.…”