The impact of hydrostatic pressure and temperature on the binding energy, linear, third-order nonlinear, and total optical absorption coefficients and refractive index changes of a hydrogenic donor impurity confined in GaAs/AlxGa1-xAs double quantum dots

Within the effective-mass approximation and by using a variational approach, we introduce a theoretical study of the binding energy, the optical absorption coefficients, and refractive index changes of a donor impurity confined in a GaAs/AlxGa1-xAs coupled double quantum dot system under the influence of the combined effects of temperature and hydrostatic pressure. The computations have been done for a double quantum dot with a realistic finite potential well in the parabolic band approximation. Our numerical results show that the donor electronic state and the photon energy dependence of the linear, third-order nonlinear, and total optical absorption coefficients as well as the refractive index changes of the system are strongly affected by the shallow-donor impurity position, hydrostatic pressure, temperature, dimensions of the system, and the Aluminum concentration. We remark that the binding energy depends on the structure size and on the donor impurity position. We have also found that the donor binding energy decreases with increasing temperature for special locations of the impurity along the growth direction of the structure. We noticed that the hydrostatic pressure and temperature have a significant impact on the optical absorption coefficients and the refractive index changes depending on the position of donor impurity. Moreover, the optical properties are forcefully influenced by the size of the system.