Real- and reciprocal-space topology in centrosymmetric square net Eu systems

Square-net materials can host diverse physical properties, including real- and reciprocal-space topology. These properties are achieved even without geometric frustration or anisotropic interactions. In this talk, I will discuss the square-net lattice EuRhAl₄Si₂, an antiferromagnet below T_N = 11.4 K. The exchange and uniaxial anisotropy interactions compete, resulting in a rare ferrimagnetic “up-up-down” phase. As a result, the displays a step at 1/3 of the saturated magnetization M. More importantly, two additional much smaller steps (“-/+m”) occur near the 1/3M plateau, where m<<M. When applying a magnetic field, atomically-sharp solitons precipitate, having all the foundational credentials for a racetrack memory at the spatial limit. The experimental evidence from field-dependent magnetization and magnetoresistance measurements is corroborated by DFT calculations. We performed atomistic spin-dynamics calculations relating the interaction parameters to the 1D magnetic soliton formation.