The Effect of a Single Off-Center Shallow Donor Atom on the Binding Energy and Diamagnetic Susceptibility in a GaAs Horn Torus Quantum Dot

Abstract

In this work, we have studied an electron confined in a GaAs Horn torus quantum dot in the presence of a shallow donor impurity. Using the effective mass approximation and by considering an infinite confinement potential, the Schrödinger equation was calculated by the finite difference method. The electron-impurity binding energy and the diamagnetic susceptibility are studied for different geometric sizes of the Horn torus. In addition, the effect of the radial and angular positions of the shallow donor impurity on the binding energy and the diamagnetic susceptibility are examined. The results show that the binding energy is much higher at small sizes of the nano system. Also, the diamagnetic susceptibility exhibits a symmetric behavior as a function of the angular position of the shallow impurity donor unlike that when the impurity moves radially. The influences of these parameter variants help us to better understand the effects of the size of the quantum dot and the position of the donor impurity, which improve the sensitive of the opto-electronic devices.