Binding energy of hydrogenic donor impurity in GaAs / Ga 1 _xAl_xAs concentric double quantum rings: Effects of geometry, hydrostatic pressure, temperature, and aluminum concentration

摘要

We consider the effects of hydrostatic pressure, temperature, aluminum concentration and impurity position on hydrogen-like donor binding energy in GaAs/Ga1_xAl_xAs concentric double quantum rings. The ground state energy and the impurity wave function are calculated using the variational method. For the hydrostatic pressure effects the Γ-X crossover has been taken into account. The probability density of electron without electron-impurity interaction have been investigated for different values of the sizes of the structure. The dependencies of the binding energy on geometry of the structure, hydrostatic pressure, temperature, aluminum concentration and impurity positions have been also investigated. The results show that the binding energy is an increasing (decreasing) function of the hydrostatic pressure and aluminum concentration (temperature). Additionally we have found that when the impurity is placed within the inner ring, the binding energy behavior strongly depends on the widths of the outer ring and coupling barrier.