Experimental Characterization of the Interface Properties between MnSe and Bi₂Se₃

In this work, we report results from exploring novel interface phenomena between thin films of nominally antiferromagnetic MnSe and Bi2Se3 topological insulator grown by MBE. Near the monolayer thickness limit, MnSe may mimic a pure ferromagnet layer. In-situ ARPES data collected from that limiting case shows the evolution of a Zeeman gap deriving from an exchange interaction. We show density functional theory calculations that are consistent with ARPES measurements of the interface. We’ve also studied the magnetic phenomena from unusually thick MnSe/Bi2Se3 heterostructure superlattices grown by MBE. Both x-ray diffraction and transmission electron microscopy show excellent crystalline order and well defined superlattice structure. We will present magnetization measurements that are consistent with pure ferromagnetic signatures, and we will discuss transport properties.