Effects of photoluminescence polarization in semiconductor quantum wells subjected to an in-plane magnetic field

Abstract

The strong effects of optical polarization anisotropy observed previously in quantum wells subjected to an in-plane magnetic field receive a complete description within the microscopic approach. The theory we develop involves two sources of optical polarization. The first source is due to correlations between electron and heavy-hole (HH) phases of $\ensuremath{\psi}$ functions arising due to electron Zeeman spin splitting and joint manifestation of low-symmetry and Zeeman interactions of HH's in an in-plane magnetic field. In this case, four possible phase-controlled electron-HH transitions constitute the polarization effect, which can reach its maximal amount $(\ifmmode\pm\else\textpm\fi{}1)$ at low temperatures when only one transition survives. The other polarization source stems from an admixture of excited light-hole states to HH's by low-symmetry interactions. The contribution of this mechanism to the total polarization is relatively small but can be independent of temperature and magnetic field. An analysis of the different mechanisms of HH splitting exhibits their strong polarization anisotropy. The joint action of these mechanisms can result in new peculiarities, which should be taken into account for an explanation of different experimental situations.