Влияние J-J-взаимодействия возбужденных состояний редкоземельного иона Pr-=SUP=-3+-=/SUP=- на магнитополяризованную люминесценцию празеодим-иттриевого граната-алюминия

The spectra of luminescence and magnetic circular polarization of luminescence of praseodymium–yttrium aluminum garnet Pr^3+ : Y_3Al_5O_12 (PrYAG) are studied in the visible spectral region at temperature T = 300 K. An analysis of spectral dependences of magnetooptical and optical spectra makes it possible to identify optical 4 f –4 f -transitions between Stark sublevels of multiplets ^3 P _0, ^3 P _1, ^3 Н _5, and ^3 Н _6 in PrYAG. It was shown that an important role in the spectrum of the degree of magnetic circular polarization of luminescence of this paramagnetic garnet is played by the effect of quantum-mechanical J – J mixing of states of Stark singlets ^3 Н _5 and ^3 Н _6 of non-Kramer rare-earth ion Pr^3+ in the “green” luminescence band related to forbidden 4 f → 4 f transition ^3 P _0 → ^3 Н _5 in the visible spectral region. To interpret the spectra of magnetic circular polarization of luminescence, the energy of experimentally determined Stark sublevels of multiplets under study, their irreducible representations and wave functions determined by numerical simulation of the energy spectrum of the rare-earth ion Pr^3+ in the garnet structure are used.

Магнитная циркулярная поляризация фотолюминесценции экситонов

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.