Circularly polarized electroluminescence of quantum-size InGaAs/GaAs heterostructures with ferromagnetic metal-GaAs Schottky contacts

摘要

Electroluminescence (EL) of InGaAs/GaAs heterostructures with quantum wells and ferromagnetic metal (Co, Ni)/GaAs Schottky contacts has been studied in magnetic fields up to 10 T at a temperature of 1.5 K. The EL line corresponding to the recombination of electrons with injected holes exhibits splitting into components corresponding to the Landau levels in the applied magnetic field and shows circular polarization that significantly exceeds the level typical of such structures with nonmagnetic (Au/GaAs) contacts. The degree of circular polarization (P (EL)) exhibits a nonmonotonic dependence on the applied magnetic field and is correlated with the filling of Landau levels. The maximum degree of circular polarization reached in the heterostructures studied is P (EL) = 40%.