Investigation of the effect of the interfacial exchange coupling on the topological surface states of Bi2Se3 in the van der Waals heterostructures Bi2Se3/ magnetic transition metal dihalides

Main objective of the proposed experiment is an investigation of the effect of the interfacial exchange coupling on the topological surface states of Bi2Se3 in the van der Waals heterostructures CoBr2/Bi2Se3, FeBr2/Bi2Se3 and NiCl2/Bi2Se3. We will perform detailed measurements of the electronic band structure and will elucidate both the effect of the moiré reconstruction and magnetic ordering (where the measurements below and above the ordering temperature are feasible). Clear observation of the interactions between the surface state and the overlayer TMDH states will require a tunable photon energy to reduce the relative intensity of the bulk states, a smaller spot size to improve the angular/momentum resolution, along with an advanced cryomanipulator (to achieve lower temperatures) and electron analyser to further improve the resolution. These requirements are only met by state-of-the-art, synchrotron-based stations, such as LOREA