Magnetic-field-tunable photoluminescence transitions in antiferromagnetic EuTe epilayers layers with an effective g factor of 1140

Narrow photoluminescence transitions of excitons in antiferromagnetic layers of EuTe grown by molecular beam epitaxy are reported. At low temperatures, two excitonic peaks are observed at around 1.9 eV with an additional broad emission band at 1.5 eV that is attributed to defects. With applied magnetic field, the excitonic transitions shift linearly by -34 meV/T to smaller energies with a total shift of more than 240 meV at 7.2 T. At T=2 K, the observed magnetic field dependence corresponds to an effective g factor of 1140, which is independent of applied field. The observed magnetic field tunability of the excitonic transitions is explained by the formation of magnetic polarons. (C) 2001 American Institute of Physics.