Atomic scale study of BiSb/MnGa interfaces toward understanding the structure of novel magnetic/topological devices

In the last decades, much effort has been put into designing more efficient, fast, and small, non-volatile information storage devices, like solid state disks (SSD) and random-access memory (RAM). Most of the reports proposed magnetic tunnel junctions to achieve perpendicular magnetic anisotropy (PMA), but less effort has been paid into the study of topological-magnetic junctions to use the giant spin Hall effect of the topological materials to induce magnetization switching into ferromagnetic materials for its application in magnetoresistance random access memory (MRAM). Experimental reports have confirmed topological-magnetic junctions as promising MRAM devices, however, atomic-scale investigations are yet to be carried out. Here we report the construction of BiSb|MnGa junctions at atomic-scale. We demonstrated that even when BiSb is not topologically intrinsic, it may facilitate a spin-orbit torque into the MnGa that leads to an easy magnetization switching. Also, we found atomistic structures with small mismatch parameters between BiSb and MnGa to compare with experimental reports.