Fresnel diffraction imaging of surface structures using coherent resonant X-ray scattering

The coherent X-ray imaging technique, which can image antiferromagnetic domains and domain walls in real space and real-time, opens up a new avenue for understanding antiferromagnetic materials in spintronic devices. Despite the great potential of the technique, the mechanism of seeing such images is elusive. Unlike interference-free X-ray reflection topography images, our technique detects interference arising from phase differences between structures within the materials - either antiferromagnetic or structural. To understand the imaging mechanism in the coherent X-ray imaging technique, we investigated the surface structure: Cr metal stripes deposited on MnBi₂Te₄ single crystal. We found that interference occurs from our structure, and the Fresnel diffraction integral in the near field can model the observed interference patterns.