Fig. 1: Dense Weyl Fermi arcs in a twisted bi-block meta-crystal.

a Arcless surface states of Weyl metamaterials on a slightly gapped interface. b Fermi arcs of twisted bi-block Weyl metamaterials on the interface. There are eight Weyl points in total. The blue (red) color indicates the top (bottom) Weyl points, while circles and dots represent opposite charges. c Periodic spatial distribution of Weyl metamaterials constructs Weyl meta-crystal, where the arcless surface states are also periodically distributed. The gray square indicates the top Weyl meta-crystal’s first Brillouin zone (top FBZ). d Dense distribution of twisted Weyl points and Fermi arcs on the interface of twisted bi-block Weyl meta-crystal. The corresponding real space schematic views are given accordingly. e Unhybridized Fermi arcs when the two surfaces are fully decoupled, e.g., h → ∞. f Hybridized Fermi arcs when \(h\to 0\) with the twisting angle \(\theta=30^\circ\).