Determination of the values of hole-mixing coefficients due to interface and electric field in GaAsÕAlxGa1ÀxAs superlattices

Numerical calculations within the envelope function framework have been performed to analyze the relations between the magnitude of in-plane optical anisotropy and the values of the additional hole-mixing coefficients due to interface and electric field in ~001! symmetric GaAs/AlxGa12xAs superlattices for light propagating along the @001# direction. It is found that the heavyand light-hole states are mixed independently by interface and electric field. The numeric results demonstrate that the line shape of the in-plane anisotropic spectrum is determined by the ratio of the two hole-mixing coefficients. Theoretical analysis shows that with the help of simple calculation of the anisotropy at k50, reliable values of the hole-mixing coefficients can be determined by reflectance-difference spectroscopy ~RDS! technique, demanding no tedious fitting of experimental curves. The in-plane optical anisotropy measured by RDS provides a new method of getting the information on buried interfaces through the value of the hole-mixing coefficient due to interface.