Field driven evolution of periodic antiferromagnetic skyrmion in non-centrosymmetric semiconducting monolayer

Antiferromagnetic skyrmions are topologically protected, stable nanoscale spin textures with countable particle-like properties, which are resistant to skyrmion Hall effect, and suitable for high-density data storage spintronic applications. However, the absence of long-range periodic antiferromagnetic skyrmion order in dynamically stable single-layer semiconducting materials hinders the compatibility and integrability of skyrmion-based devices with existing semiconductor-based technologies. Here, in this work, we demonstrate the nucleation of periodic antiferromagnetic skyrmions in a Janus non-centrosymmetric semiconducting monolayer, MnBrCl. In the Janus monolayer with a unique antiferromagnetic double-stranded helical ground state configuration of magnetic moments, a periodic antiferromagnetic skyrmion is nucleated under a magnetic field, which has not been reported previously. We have thoroughly investigated the microscopic origin of this periodic, topologically protected structure and propose a four-sublattice framework that explains the field-driven nucleation of antiferromagnetic skyrmions. This mechanism of antiferromagnetic skyrmion evolution, based on the four-sublattice framework, offers a new perspective on the formation of periodic antiferromagnetic skyrmions. Our analysis also provides deeper insight into the controllability of magnetic topology in Janus non-centrosymmetric material. Further, the magnetic tunability of the nucleated periodic AFM skyrmions suggests suitability of the materials for parallel processing applications in multi-state memory devices and neuromorphic computing, thereby enriching the domain of AFM skyrmion based spintronic.