Single antiferromagnetic MnTe (sub)monolayers in CdTe/CdMgTe quantum wells

Antiferromagnetic MnTe (sub)monolayers inserted into nonmagnetic CdTe/CdMgT e quantum wells are investigated by magneto-optical spectroscopy. In partic ular, the Zeeman splitting is determined from polarization dependent photol uminescence excitation experiments. Rapid thermal annealing (RTA) is applie d to diffuse Mn out of the (sub)monolayer barriers into the quantum well. T he resulting Mn diffusion leads to a substantial increase of the Zeeman spl itting. Furthermore, the annealing induced broadening of the MnTe (sub)mono layer barrier in the well is accompanied by a decrease of the barrier heigh t, leading to a blue shift or a red shift of the e(1)-hh(1) transition, dep ending on the detailed sample structure. A comparison of the observed energ y shifts with model calculations allows us to estimate the thickness of the MnTe barriers. These are found to be very close to their nominal values be fore annealing, regardless of the chosen MnTe band offset and effective mas ses.