Electric and magnetic field effects on the binding energy of a hydrogenic donor impurity in a coaxial quantum well wire

Abstract

The effect of both an electric and magnetic field on the hydrogenic binding energy of a shallow donor impurity in a coaxial GaAs-(Ga, Al)As quantum well wire (QWW) has been investigated as a function of the impurity position and barrier thicknesses for different values of the applied magnetic and electric field strengths. Within the effective mass approximation, the ground-state energy in the presence of a uniform magnetic field applied parallel to the wire axis has been calculated using the fourth-order Runge–Kutta method. The ground state binding energy under applied electric field has been studied with a variational approach. The two sharp increase in the binding energy have observed for the donor impurity located at outside of the center under the critical electric and magnetic field values. However, for the electric field off the binding energy monotonously decrease with increasing magnetic field strength up to a critical magnetic field and then a sharp decrease is seen before reaching a constant value. For the impurity located at the center, the abrupt deviations of the binding energy strongly depend not only on the electronic confinement, but also on the electric and magnetic field strength. We expect that these results will be useful in technological applications.