Floquet Möbius topological insulators
Phys. Rev. B 112, 134302 – Published 7 October, 2025
DOI: https://doi.org/10.1103/7y54-n6js
Abstract
Möbius topological insulators have dispersive edge bands with Möbius twists in momentum space, which are protected by the combination of chiral and -projective translational symmetries. In this work, we reveal a unique type of Möbius topological insulator, whose edge bands can twist around the quasienergy of a periodically driven system and are thus of Floquet origin. By applying time-periodic quenches to an experimentally realized Möbius insulator model, we obtain interconnected Möbius edge bands around zero and quasienergies, which can coexist with a gapped or gapless bulk. These Möbius bands are topologically characterized by a pair of generalized winding numbers, which are integer-quantized as a result of an emergent chiral symmetry at a high-symmetry point in momentum space. Numerical investigations of the quasienergy and entanglement spectra provide consistent evidence for the presence of such Möbius topological phases. A protocol based on the adiabatic switching of edge-band populations is further introduced to dynamically characterize the topology of Floquet Möbius edge bands. Our findings thus extend the scope of Möbius topological phases to nonequilibrium settings and unveil a unique class of Möbius-twisted topological edge states without static counterparts.