Topology: a new twist to electrons in quantum materials

Over the past two decades, topology has become an increasingly valuable tool in condensed matter research, providing a radically different way of thinking about materials and enabling the prediction and discovery of exotic states with intriguing physical properties. Topological metals and semimetals exhibit exceptional transport behaviour due to the existence of low energy quasiparticles which resemble relativistic fermions. A particular interest is to identify materials in which the topology of the electrons can be controlled by magnetic order or magnetic fields.

In this talk, I will give a general introduction to the field of topological electronic bands and then discuss how magnetic structures can couple to electronic band topology, drawing examples from very recent studies on several intermetallic compounds, including candidates for Weyl semimetals and axion insulators. I especially wish to highlight the strengths of scattering experiments using advanced neutron and synchrotron radiation techniques for probing important aspects of the magnetic structures.