Unveiling the nanoscale magnetic properties of van der Waals antiferromagnetic materials*

Owing to their intrinsic, strong spin fluctuations and multifaceted tunability, van der Waals (vdW) magnetic thin films have garnered widespread interest. However, understanding and controlling novel phases in these materials require quantitative knowledge of their magnetic properties at the nanoscale.

The nitrogen-vacancy (NV) center, especially scanning NV magnetometry, has proven to be an excellent tool for nanoscale imaging of vdW materials due to its superior combination of high magnetic field sensitivity and spatial resolution. In this study, we address the nanoscale magnetic textures in vdW antiferromagnetic (AFM) 2D magnets down to the monolayer limit using the magnetic stray field images obtained by scanning NV magnetometry at cryogenic temperatures. Our result enhances the understanding of different magnetic phases, the formation of domain walls, and magnetic anisotropies and exchange interactions in these systems. Moreover, we explore the possibility to control AFM orders  as  a route to achieve AFM-based memories.