Pressure effect on the diamagnetic susceptibility of donor in HgS and GaAs cylindrical quantum dot

Abstract

The binding energy and diamagnetic susceptibility of shallow hydrogenic impurity in cylindrical quantum dot is calculated using a variational approach within the effective mass approximation, as a function of dot size when the static pressure and the magnetic field are applied simultaneously. We describe the quantum confinement by an infinite deep potential; the numerical calculations are performed for HgS, which is a narrow gap, and GaAs, a large gap semiconductor. The results show that the diamagnetic susceptibility increases with the reduction in dot sizes and decreases when the hydrostatic pressure increases. We have shown that diamagnetic susceptibility strongly depends on size of the nanostructure and decreases with increasing size of the quantum dot and tends toward the limit of the bulk (−1, 1 a.u.) (increase in diamagnetic susceptibility in absolute value). We have found that the displacement of the impurity from the center of the quantum dot to the edge causes a decrease in the diamagnetic susceptibility. The absolute value of diamagnetic susceptibility of donors in GaAs is lower than in HgS.