Quantum Geometry and Transport of Collective Excitations in (Non-)Magnetic Insulators
Quantum geometric properties of band structures and their signatures in experiments have driven condensed matter research over the past decades. This SPICE workshop will focus on recent theoretical and experimental advances in the topological properties of bands formed by magnetic and hybrid bosonic excitations. While the topology of electron bands is well understood, with unambiguous experimental tools to probe theoretical predictions, their bosonic analogs pose challenges. Although bosonic topological excitations, such as magnon Chern bands, Weyl and Dirac semimetals, and nodal-line semimetals have emerged, the lack of quantized responses and the ambiguity of thermal Hall and Nernst effects prevent their distinct experimental identification. Furthermore, traditional spectroscopic methods for resolving bosonic modes, such as inelastic neutron scattering, lack the contrast to resolve topological boundary states. One possible route to bring the topological excitations under control is to make use of highly tunable platforms, such as magnonic crystals and stacked van der Waals layers. Additionally, the ease of hybridization of magnonic excitations with phonons, photons, and plasmons can provide novel opportunities to directly probe the topological fingerprint.
With this workshop, we aim to provide a forum where experts and students can discuss the latest developments, challenges, and future directions in topological magnetism. Some exciting challenges that we aim to address include:
-Identify direct experimental signatures for topological bosonic excitations
-Explore the impact of many-body interactions on the quantum geometry of the single particle spectrum and transport
-Identify the microscopic origins of thermal Hall conductivity in magnetic and non-magnetic insulators
-Engineer the quantum geometry and topology of collective excitations by non-Hermitian, non-equilibrium, and Floquet control
For videos of the talks and further information, please visit the workshop home page.