Topological magnets—their basic science and potential applications

Abstract

The performance limitations of conventional electronic materials pose a major problem in the era of digital transformation (DX). Consequently, extensive research is being conducted on the development of quantum materials that may overcome such limitations, by utilizing quantum effects to achieve remarkable performances. In particular, considerable progress has been made on the fundamental theories of topological magnets and has had a widespread impact on related fields of applied research. An important advance in the field of quantum manipulation is the development of the technology to control the quantum phase of conduction electron wavefunctions through the spin structure. This new technology has led to the realization of phenomena that had been considered infeasible for more than a century, such as the anomalous Hall effect in antiferromagnets and the giant magneto-thermoelectric effect in ferromagnets. This review article presents the remarkable properties of Weyl antiferromagnets and topological ferromagnets, which have been discovered recently. Additionally, this paper examines the current status of how advances in the basic principles of topological magnetism are facilitating the development of next-generation technologies that support the DX era, such as energy harvesting, heat flow sensors, and ultrafast nonvolatile memory.

Large Anomalous Hall Effect at Room Temperature in a Fermi‐Level‐Tuned Kagome Antiferromagnet

“…Full logarithmic plot of the magnetization (M) dependence of the AHC of Mn 2.4 Ga, topological magnets, [23,30,65] and conventional ferromagnets. [18,36,66] The red shades mark the regions where 𝜎 H is linearly related to M for conventional magnets. While the topological magnets surpass this linear relation and are located in the blue-shaded region.…”