Discovery and characterization of a new type of domain wall in a row-wise antiferromagnet

Antiferromagnets have recently moved into the focus of application-related research, with the perspective to use them in future spintronics devices. At the same time the experimental determination of the detailed spin texture remains challenging. Here we use spin-polarized scanning tunneling microscopy to investigate the spin structure of antiferromagnetic domain walls. Comparison with spin dynamics simulations allows the identification of a new type of domain wall, which is a superposition state of the adjacent domains. We determine the relevant magnetic interactions and derive analytical formulas. Our experiments show a pathway to control the number of domain walls by boundary effects, and demonstrate the possibility to change the position of domain walls by interaction with movable adsorbed atoms. The knowledge about the exact spin structure of the domain walls is crucial for an understanding and theoretical modelling of their properties regarding, for instance, dynamics, response in transport experiments, and manipulation. Antiferromagnets (AFM) exhibit faster magnetization dynamics, and have immunity to stray fields, making AFMs attractive for spintronic devices. Here, the authors investigate the behaviour of domain walls in AFMs, and find a new type domain wall, a superposition of two adjacent rotational domains.

Automated summary

Research on antiferromagnets has shifted focus to potential applications in spintronics devices, with experimental investigations into the detailed spin texture of antiferromagnetic domain walls using spin-polarized scanning tunneling microscopy. A new type of domain wall, a superposition state of adjacent domains, has been identified, indicating the potential for controlling domain walls through boundary effects and interaction with movable adsorbed atoms. Understanding the exact spin structure of domain walls is crucial for theoretical modeling and manipulation, given the unique properties of antiferromagnets in faster magnetization dynamics and immunity to stray fields.