Coupling between magnetism and topology: From fundamental physics to topological magneto-electronics

Abstract

Magnetism and topological physics are both well-developed disciplines, and their combination is a demand and foundation for the development of next-generation magneto-electronics. Magnetic topological materials are important products of coupling between magnetic order and topological physics, providing material carrier and regulatory degrees of freedom for novel topological physics. Magnetic Weyl semimetals realize Weyl fermion states under time-reversal symmetry breaking, leading to a host of novel magnetic, electric, thermal, and optical effects through enhanced Berry curvature originating from topology. The interaction between Weyl electrons and magnetic order also establishes topological electronic physics as a new principle and driving force for magneto-electronic applications. At present, the primary task and characteristic of the first development stage of magnetic topological materials is to discover new states and effects, while the understanding of interaction between topologically nontrivial electrons in momentum space and magnetic order in real space has received attention of researchers. The comprehensive advances of these two stages will accumulate the physical foundation and application explorations for topological magneto-electronics. This paper focuses on the two development stages of magnetic topological materials and discusses three aspects: (i) proposal and realization of strategy for magnetic topological materials; (ii) exploration of electronic states with nontrivial topology under uniform magnetic order and their associated novel physical properties; (iii) the interaction between localized magnetic states and topological electrons. It provides an in-depth discussion on current hot topics and development trends in the field, and future development in topological magneto-electronics, thereby assisting in the future development of topological spin quantum devices.