Switching Behavior of Carbon Chains Bridging Graphene Nanoribbons: Effects of Uniaxial Strain

Recently, several experiments [1,2] demonstrated the stability of chain-like carbon nanowires bridged between graphene nanoribbons, paving the way for potential applications in nano-devices. On the basis of density functional tight-binding calculations, we demonstrated switching for chains terminated with a five-membered ring under an applied strain, serving as a model for morphological changes in realistic materials. Electron transport calculations showed an increase of up to 100{\%} in the output current, achieved at a reverse bias-voltage of 2V and an applied strain of just 1.5{\%}. Structural analysis suggested that the switching is driven by conformational changes, in our case triggered by the formation and annihilation of a five-membered ring at the interface of the chain-graphene edge. In addition, we showed that a five-membered ring can easily be formed at the interface under a source-drain bias or through a gate voltage. This mechanism can serve as an explanation of experimentally observed conductance for the materials. \\[4pt] [1] Jin, C.; Lan, H.; Peng, L; Suenaga, K.; Iijima S. \textit{Phys. Rev. Lett.} \textbf{2009}, 102, 205501. \\[0pt] [2] Chuvilin, A.; Meyer, J. C.; Algara-Siller, G.; Kaiser, U. \textit{New J. Phys.} \textbf{2009}, 11, 083019