Effect of intermolecular distance and contact hollow-type on the transport properties of parallel atomic wires

We use non-equilibrium Green's function combined with density functional theory to investigate the electronic transport properties of two parallel molecular wires made of carbon atomic chains (triynes) capped with thiol. The results show that the transport behaviors clearly depend on the intermolecular distance when the two wires are separated by a relatively small distance. However, with increasing the wire spacing, the transport properties are dramatically affected by the molecule–electrode contact hollow-type and insensitive to the intermolecular distance. A quantum interference mechanism is proposed to interpret the contact hollow-type dependence of transport properties at large intermolecular distance.