The topological properties of magnets, encoded in the reciprocal space distribution of the
Berry phase, have caused a revolution in our understanding of their transport properties.
The discovery that the non-trivial geometry of states in a solid is ultimately related to
the orbital properties of electrons allows us to predict from theoretical arguments a
pronounced orbital magnetism in various situations ranging from Rashba systems to Chern
insulators. Moreover, we demonstrate that a combination of complex geometry in real and
reciprocal spaces leads to an emergence of topological orbital magnetism in non-collinear
magnets, which overall opens new vistas in large current-induced orbital magnetization
response and magnetization manipulation in antiferromagnets. Finally, we predict that in
insulating systems with non-trivial topologies the strength of the magneto-electric response
as manifested in the magnitude of the current-induced spin-orbit torques and Dzyaloshinskii-Moriya
interaction can exceed significantly that of conventional metallic magnets, which opens new
perspectives in dissipationless control of magnetization in magnetic materials.
|