Full anisotropy control of a topologically-rich antiferromagnet

We recently made the pioneering discovery of a family of topological solitons, in the classic oxide antiferromagnet (AFM) a-Fe2O3, which are stable at room temperature. Such AFM solitons could emerge as prime candidates to build unconventional ultra-fast spintronic devices. However, a major issue is that AFM solitons observed thus far emerge randomly in a non-uniform magnetic background. This makes it difficult to control them individually in a targeted manner. 

To address this challenge, our project aims to redesign the magnetic energy landscape by tailoring the AFM anisotropy. We have fabricated a new class of a-Fe2O3 thin film samples on vicinal crystals to introduce an in-plane anisotropy. Our recent ALBA experiment shows that we have successfully broken the basal symmetry due to the substrate miscut. Building upon this we further optimised our samples in which we observed the stabilisation of single AFM domain states in X-ray PEEM. 

In this continuation proposal, we plan to use X-ray linear dichroism to confirm the validity of our observations over a large sampling area. Specifically, we plan to study the effect of film thickness (5-15nm) and miscut angle (0°-4°) on the AFM anisotropy and domain distribution. These results will pave the way for building novel AFM devices where individual topological solitons can be stabilised and controlled in a targeted manner.