Research Highlights
Interferometry of Non-Abelian Band Singularities and Euler Class Topology
Protocols for measuring exotic topological charges emerging from an intricate dance of electrons in materials.
Illustration of non-Abelian braiding of band singularities, which can be probed by the proposed interferometry schemes. Passing atoms through band nodes reveals the relative frame charges and allows for measuring the resulting multigap topological invariant.
Topological singularities play a central role in the recently discovered multi-gap topological phases,
whereby nodes carry non-Abelian charges and display novel braiding properties that are path dependent.
Whilst isolated band nodes have been probed experimentally, multi-gap topologies have been elusive and the
ability to measure the relative non-Abelian charges of different band singularities has been missing.
Reporting in Physical Review Letters as an Editors' suggestion, we reveal an important physical manifestation of the non-Abelian nature of these charges and demonstrate two viable
techniques directly implementable in state-of-the-art experiments. Our results present a feasible avenue for measuring
non-Abelian charges of band nodes and the direct experimental verification of braiding procedures, which can be applied in
a variety of settings including the recently discovered anomalous non-Abelian phases arising under periodic driving.