Kagome network of miniband-edge states in double-aligned graphene–hexagonal boron nitride structures

Twistronic heterostructures have recently emerged as a new class of quantum\nelectronic materials with properties determined by the twist angle between the\nadjacent two-dimensional materials. Here we study moir\\'e superlattice\nminibands in graphene (G) encapsulated in hexagonal boron nitride (hBN) with an\nalmost perfect alignment with both the top and bottom hBN crystals. We show\nthat, for such an orientation of the unit cells of the hBN layers that locally\nbreaks inversion symmetry of the graphene lattice, the hBN/G/hBN structure\nfeatures a Kagom\\'e network of topologically protected chiral states with\nenergies near the miniband edge, propagating along the lines separating the\nareas with different miniband Chern numbers.\n