W. Heiss et al., Giant tunability of exciton photoluminescence emission in antiferromagnetic EuTe - art. no. 165323, PHYS REV B, 6316(16), 2001, pp. 5323
The photoluminescence properties of antiferromagnetic EuTe layers grown by
molecular-beam epitaxy are reported. At low temperatures, two excitonic pho
toluminescence peaks are observed at 1.92 and 1.88 eV with a full width at
half maximum of about 10 meV. With applied magnetic field, these excitonic
transitions shift linearly by -34 meV/T to smaller transition energies with
a total shift of more than 240 meV at 7.2 T. This is the largest tuning ra
nge observed in any semiconductor. The observed magnetic field and temperat
ure dependence of the luminescence lines is explained by the formation of l
arge magnetic polarons due to exchange interactions between the d-like elec
trons in the conduction band and localized 4f spins.