Transport properties of short carbon wire suspended between carbon nano tube electrodes

Abstract

We have studied the transport properties of carbon wire between zigzag carbon nanotubes and armchair electrodes. The gap width between the electrodes was modulated and the corresponding conductance variation of the junction was calculated. Variation gap width caused the carbon wire changed its structure and contact geometries. It was found that transport properties of the junctions were significantly affected by the choice of chirality. For zigzag junctions ON and OFF states were observed. These corresponded to cumulene and polygne structures respectively. Oscillatory behaviour in conductance of cumulene wires with different lengths were found. It was found that odd cumulene wires have higher conductance than even cumulene wires. The calculated ON/OFF ratios of the odd wires were larger than those of even wire larger than those of even wires. The observed value of zerobias conductance was zero. Due to their semiconducting character of zigzag electrodes, switching behavior was observed at high bias voltages. The obtained results were compared with previously calculated and observed values were found in good agreement.