Semimetallic and semiconducting graphene-h BN multilayers with parallel or reverse stacking

We theoretically investigate three-dimensional (3D) layered crystals of alternating graphene and h BN layers with different symmetries. Depending on the hopping parameters between the graphene layers, we find that these synthetic 3D materials can feature semimetallic, gapped, or Weyl semimetal phases. Using first-principles calculations to parametrize the low-energy Hamiltonians we establish the most likely electronic phases. Our results demonstrate that 3D crystals stacked from individual 2D materials represent a synthetic materials class with emergent properties different from their constituents.