“Antisymmetric interlayer exchange coupling in magnetic multilayers”

Dr. Myung Hwa Jung
Department of Physics, Sogang University

Dec. 11 (Fri.), 02:30 PM
Online seminar
https://kaist.zoom.us/j/89400733670
회의 ID: 894 0073 3670
암호: 703454

Abstract:
The exchange interaction governs static and dynamic magnetism. This fundamental interaction comes in two flavors – symmetric and antisymmetric. While the symmetric interaction leads to ferro- and antiferromagnetism, the antisymmetric interaction has attracted significant interest owing to its major role in promoting topologically non-trivial spin textures that promise fast, energy-efficient devices. So far, the antisymmetric exchange interaction has been found to be rather short–ranged and limited to a single magnetic layer. Here, we report a long-range antisymmetric interlayer exchange interaction in perpendicularly magnetized synthetic antiferromagnets with parallel and antiparallel magnetization alignments. Asymmetric hysteresis loops under an in-plane field reveal a unidirectional and chiral nature of this interaction, resulting in canted magnetic structures. We explain our results by considering spin-orbit coupling combined with reduced symmetry in multilayers. Our discovery of a long-range chiral interaction provides an additional handle for engineering magnetic structures and could enable three-dimensional topological structures.