Magnetic Circular Polarization of Exciton Photoluminescence

Experimental and theoretical studies of circular polarization of photoluminescence of excitons (MCPL) in semiconductors placed in an external magnetic field are reviewed. The advantage of the MCPL method is its relative simplicity. In particular, it does not require spectral resolution of the Zeeman sublevels of an exciton and may be applied to a wide class of objects having broad photoluminescence spectral lines or bands: in bulk semiconductors with excitons localized on the defects of the crystal lattice and composition fluctuations, in structures with quantum wells and quantum dots of types I and II, in two-dimensional transition metals dichalcogenides and quantum microcavities. The basic mechanisms of the magnetic circular polarization of luminescence are considered. It is shown that either known mechanisms should be modified or additional mechanisms of the MCPL should be developed to describe the polarized photoluminescence in newly invented nanosystems.