Pressure Induced Effective Exciton g-Factor in a Strained Ga_(0.2)In_(0.8)As/GaAs Quantum Dot

摘要

The pressure induced exciton binding energy in a strained Ga_(0.2)In_(0.8)As/GaAs quantum dot is investigated taking into account the anisotropy, non-parabolicity of the conduction band and the geometrical confinement. The pressure related Γ-X crossover is taken into account. The optical transition energy as a function of dot radius is discussed in the presence of hydrostatic pressure. The dependence of the effective excitonic g-factor as functions of dot radius and the hydrostatic pressure is numerically measured. The interband optical heavy hole excitonic absorption spectra are obtained for various hydrostatic pressure in the Ga_(0.2) In_(0.8) As/GaAs quantum dot. It has been found that (i) Landé factor increases with the hydrostatic pressure, (ii) the resonant peak of absorption coefficient decreases with the magnitude above the transition pressure, 53 kbar (Γ-X crossover) and the exchange enhancement splitting not only increases with the geometrical confinement but also with the pressure values.