Lorentz transmission electron microscopy for magnetic skyrmions imaging

Magnetic skyrmions have interesting properties, including their small size, topological stability, and extremely low threshold current for current-driven motion. Therefore, they are regarded as promising candidates for next-generation magnetic memory devices. Lorentz transmission electron microscopy (TEM) has an ultrahigh magnetic domain resolution (~2 nm), it is thus an ideal method for direct real-space imaging of fine magnetic configurations of ultra-small skyrmions. In this paper, we describe the basic principles of Lorentz-TEM and off-axis electron holography and review recent experimental developments in magnetic skyrmion imaging using these two methods.