Se/EuSe heterostructures*

Magnetic topological insulators have been greatly studied in the past decades to achieve and enhance the critical temperature of the Quantum anomalous Hall. One way to induce magnetization into TIs is by using the magnetic proximity effect (MPE). It will introduce a magnetic exchange gap which has never been directly measured. Pb_1-xSn_xSe (0.161-xSn_xSe/EuSe heterostructures with x=0.1-0.3 and probe the exchange induced gap at the interface using magnetooptical spectroscopy. Landau level transitions can be extracted as of 4T and are fitted using a k·p quantum well model. The high mobility and low Fermi energy of these heterostructures will allow to directly probe the energy gap induced by the MPE.