Correlation between electron spin and light circular polarization in strained semiconductors

Influence of strain on the correlation between the electron polarization P-s and the circular polarization of the emitted light P-cir is studied for heterostructure semiconductors within the Luttinger-Kohn model. In the unstrained spin polarized semiconductor, the heavy-hole as well as light-hole wave functions have equal weight expansions of the basis states. Therefore, the relation between P-cir and P-s is just a factor -1/2. In the case of uniaxial strain this factor varies with the luminescence photon energy, between roughly -0.9 and 0.8. This provides a sensitive method for detection of strain in bulk semiconductor and also suggests a tool for efficient optical excitation of spin polarized conduction electrons in a strained semiconductor.