Anisotropic Electronic Structure and Transport Properties of the H-0 Hyperhoneycomb Lattice

Carbon, being one of the most versatile elements of the periodic table, forms solids and molecules with often unusual properties. Recently, a novel family of three-dimensional graphitic carbon structures, the so-called hyperhoneycomb lattices, has been proposed, with the possibility of being topological insulators. In this work, we present electronic structure calculations for one member (H-0) of this family, using Density Functional Theory and non-equilibrium Green’s functions transport calculations to show that the H-0 structure should have strongly anisotropic electronic properties, being an insulator or a conductor depending on the crystalline orientation chosen for transport. Calculations in the framework of Extended Huckel Theory indicate that these properties can only be understood if one considers at least 2nd nearest-neighbor interactions between carbon atoms, invalidating some of the conclusions of Ref. 1, at least for this particular material.