New platform for realizing non-Abelian gauge fields
In their Nature Communications work, Zoltán Guba and Lavi Upreti from the group of Tomáš Bzdušek present a new platform for combining topological band structures with non-Abelian gauge fields.
The work, carried in collaboration with Robert-Jan Slager at the University of Manchester, utilizes a crystalline construction called Cayley-Schreier lattice and provides a blueprint for implementing such lattices in synthetic crystals. Notably, the reported scheme realizes arbitrary gauge fields using solely real couplings—in contrast to formerly considered approaches that require coupling with complex phases.
Curiously, the Cayley-Schreier construction involves a rich inherent structure: the resulting Hamiltonian separates into decoupled symmetry sectors, with each sector experiencing its own emergent gauge field. As a result, a single crystalline structure can host distinct sector-dependent topological phases. The authors specifically illustrate how the Kane-Mele model—a paradigm model of two-dimensional topological insulator—can be conveniently realized in a Cayley-Schreier lattice.
Publication: Nat. Commun. 17, 4669 (2026). https://doi.org/10.1038/s41467-026-71401-3
