Single-shot switching in Tb/Co-multilayer based nanoscale magnetic tunnel junctions

•Optical writing and electrical reading of magnetic states within nanoscale ferromagnetic tunnel junctions.•Downscaling of the perpendicularly magnetized nanodevices while retaining the desired functionalities.•Correlation between the switching probability, magnetic anisotropy, and the diameter of the nanodevices.•Probing the depth-resolved hysteresis and time-resolved magnetization dynamics in a full stack magnetic tunnel junction film.