Gate Dependent One-dimensional Transport in In2O3 Nanowires

The gate-dependent one-dimensional transport of single- crystalline semiconducting In$_{2}$O$_{3}$ nanowire field effect transistors is studied at low temperature by measuring I-V and differential conductance. The In$_{2}$O$_{3}$ nanowires were synthesized by a laser ablation process to have a diameter of 10 nm and a length of 2 $\mu $m. Back gate was formed using a highly-doped silicon substrate with a gate oxide thickness of 0.5 $\mu $m. At a smaller positive gate bias, gaps at near zero source-drain bias were observed for both current and differential conductance spectra due to the absence of the density of states in the source-drain energy window. The transport can be explained by Fermi-liquid theory. On the other hand, when the Fermi energy of the nanowire moves up into the conduction band, the differential conductance of the semiconducting In$_{2}$O$_{3}$ nanowire exhibits zero-bias anomalies, following a power-law behavior similar to one-dimensional Luttinger-liquid. These results suggest that electron-electron interaction must be taken into consideration for the understanding of transport of nanowires at low temperature under a large gate bias.