Band hybridization and higher-order topological insulator state in Honeycomb-Kagome heterostructure

Heterostructures of stacked two-dimensional lattices have shown a promise in their potential for engineering novel material properties. Hexagon-shared honeycomb-kagome lattice, an archetypal example of such system, has been shown to exhibit topologically protected nodal line semimetals. In this work, we demonstrate the symmetry variants of the honeycom-Kagome lattices, which exhibit the insulating phase transitions through double band inversions characterized by higher-order topological corner states. By modifying the stacking patterns, different rotational symmetry modifies in addition to the trivial insulating phases. Finally, we show that the experimentally verifiable patterns of metallic networks occurs in the moire pattern of the honeycomb-kagome heterostructure that endeavors the non-trivial topology of the honeycomb-kagome variants.