NSF Award
1708790
Non-Technical Abstract:<br/>This project focuses on the study of the interactions that can arise at the boundary between ferromagnetic and non-magnetic materials. This interaction is key to the formation of magnetic structures that have potential as a new means to store and transmit information, and it also leads to unusual modifications of the properties of magnetic materials, important for future devices. The research teams at Bryn Mawr College and Colorado State University are taking a collaborative approach to study magnetic interactions and magnetization dynamics in order to gain new insight into the underlying physics of the interaction effects. Education for the young generation is an important component of this project. The PIs strive to involve and train students at both the undergraduate and graduate levels, especially women and students from underrepresented minority groups. The students working on this project also have the opportunity to collaborate with scientists at Argonne National Laboratory and gain hands on imaging experience. The PIs incorporate research examples from this project into teaching and outreach activities at both institutions. <br/><br/>Technical Abstract:<br/>Dzyaloshinskii-Moriya interactions (DMI) that lead to anisotropic exchange effects are rapidly gaining attention in magnetism and spintronics-related research. DMI, which arise from broken inversion symmetry and spin-orbit coupling, can occur in bulk chiral crystals and at non-magnetic/magnetic interfaces if the non-magnetic layer exhibits high spin orbit coupling. DMI promote the formation of stable chiral magnetic spin configurations such as skyrmions, and significantly modify dynamic processes in thin film systems. It has been shown that DMI can influence skyrmion and domain wall motion and that DMI lead to a nonreciprocity for surface spin waves in extended thin films. DMI should also significantly modify the dynamics in patterned magnetic nanostructures where the wavelengths of the spin dynamics are inherently short due to geometric confinement effects. In this collaborative research project, the research teams are investigating the effects of interfacial DMI on skyrmion formation and on spin dynamics in both extended and patterned multilayered films. Multilayers provide a means to stabilize submicron-sized skyrmions at room temperature by tuning not only DMI and surface anisotropies through the choice of the materials, but also the magnetostatic interactions through varying the number of repeats. The results of this project lead to new information on interfacial DMI and the effects of DMI on skyrmion formation and spin dynamics in confined geometries.
