Composite topological phases via Floquet engineering

The hybridization of different topological phases is attractive because it can facilitate the simultaneous utilization of their respective advantages. Three-dimensional (3D) higher-order topological insulators host gapless hinge states or corner states, while Weyl semimetals have novel properties such as chiral anomaly. However, so far, the general method to induce 3D composite topological phases with coexisting Weyl semimetals and higher-order topological insulators is still lacking. Here, we propose a scheme to induce this kind of composite topological phase by periodic driving and demonstrate that such a phase is the intermediate phase between anomalous Floquet higher-order topological insulators and Floquet first-order Weyl semimetals. Our results may open a possibility to realize different phases without static analogs.