Electronic transport in large systems through a QUAMBO–NEGF approach: Application to atomic carbon chains

The conductance of single-atom carbon chain (SACC) between two zigzag graphene nanoribbons (GNR) is studied by an efficient scheme utilizing tight-binding (TB) parameters generated via quasi-atomic minimal basis set orbitals (QUAMBOs) and non-equilibrium Greenʼs function (NEGF). Large systems (SACC contains more than 50 atoms) are investigated and the electronic transport properties are found to correlate with SACCʼs parity. The SACCs provide a stable off or on state in broad energy region (0.1–1 eV) around Fermi energy. The off state is not sensitive to the length of SACC while the corresponding energy region decreases with the increase of the width of GNR. ► Graphene has many superior electronic properties. ► First-principles calculation are accurate but limited to system size. ► QUAMBOs construct tight-binding parameters with spatial localization, and then use divide-and-conquer method. ► SACC (single carbon atom chain): structure and transport show even–odd parity, and long chains are studied.