Tailoring of exchange frustration and higher order exchange for the optimization of magnetic skyrmions and antiskyrmions

• Applicant: Dr. Stephan von Malottki
• Subject Area: Theoretical Condensed Matter Physics
• Term: Funded in 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 523127890

Here we explore the possibilities and limitations of exchange frustration and higher order exchange interactions (HOI) to stabilize magnetic skyrmions and antiskyrmions in 2D materials with ferromagnetic and antiferromagnetic ordering, going beyond the usual focus on DMI to stabilize these structures. First, we perform large scale automatised atomistic spin simulations on the entire parameters space of the infamous extended Heisenberg model, including exchange interactions beyond nearest neighbours and HOI. From these tens of thousands of simulations we extract the energy barriers of zero-field and sub-10 nm skyrmions and antiskyrmions, resulting in parameter criteria for data-driven magnetic material design. In the second part of the project, we apply high-throughput DFT computations to scan ultrathin film combinations of transition metals as well as Van-der-Waals heterostructures for their ability to host technological relevant skyrmions and antiskyrmions. In a first step, the material combinations will be filtered by their basic magnetic properties such as magnetic moment sizes and the energies of collinear magnetic states. For suited materials, the magnetocrystalline anisotropy, exchange interactions beyond nearest neighbours and HOI parameters will be determined in subsequent steps. Promising candidates that fulfill the parameter criteria obtained in the first part of the project will be investigated in more detail by atomistic simulations and predicted as novel skyrmion and antiskyrmion hosting materials.

• DFG Programme: WBP Fellowship
• International Connection: USA
• Host: Professor Dr. Geoffroy Hautier