Temperature and resultant dipole moment of an off-center D- impurity in a Gaussian quantum dot

Abstract

Abstract The present study investigates the variation of energy ( E ), binding energy ( E B ) and the resultant dipole moment ( D p ) of a negative donor impurity ( D − ) with on-center and off-center locations ( d ) in a GaAs three-dimensional quantum dot (3D-QD) modelled with a Gaussian confinement potential. I have performed Ritz-variational method (RVM) with a very simple wave function which contains just three-variational parameters and a Jastrow-like factor. For on-center ( D − ) impurity, it is true from [47,50] and present results that the E B is always positive and maximum at a particular size of the QD ( R c ). For off-center ( D − ) impurity especially for a large value of locations ( d ) the ( E B ) can be negative. These situations imply that the stability and instability of the system for a given range of the quantum dot size ( R ), respectively. I have obtained the temperatures of D 0 , D − impurities at which these impurities are more stable in a 3D-QD. The confinement length ( R ) and the confinement strength ( V 0 ) effects, on the resultant dipole moment ( D p ) are also investigated for various values of the impurity locations ( d ).