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

Narrow photoluminescence transitions of excitons in antiferromagnetic layer s 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 broa d emission band at 1.5 eV that is attributed to defects. With applied magne tic 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 o bserved magnetic field dependence corresponds to an effective g factor of 1 140, which is independent of applied field. The observed magnetic field tun ability of the excitonic transitions is explained by the formation of magne tic polarons. (C) 2001 American Institute of Physics.