Optically detected anti-intersection of levels of localized excitons in semiconductors

Theoretically is investigated the effect of anti-intersection of exciton levels on the intensity and polarization of radiation of quartet excitons, produced by electrons with ±1/2 spin and holes with ±3/2 spins. A set of equation is derived for stationary population of the quartet levels. The set accounts for the radiative and radiation less exciton lifetime, selective optical generation of exciton sublevels and temperature-dependent spin relaxation. Experimental and theoretical results are compared. 15 refs.; 3 figs