Cotunneling transport in ultra-narrow gold nanowire bundles

A. Loubat (1) , Walter Escoffier (2) , Lise-Marie Lacroix , G. Viau (3, 4, 5) , Reasmey Phary Tan , Julian Carrey (3) , Bénédicte Warot-Fonrose , Bertrand Raquet (2)

1 Immunologie cellulaire et moléculaire
2 LNCMI-T - Laboratoire national des champs magnétiques intenses - Toulouse
3 LPCNO - Laboratoire de physique et chimie des nano-objets
4 ITODYS (UMR_7086) - Interfaces, Traitements, Organisation et Dynamique des Systèmes
5 IMPMC - Institut de minéralogie et de physique des milieux condensés

We investigate the charge transport in close-packed ultra-narrow (1.5 nm diameter) gold nanowires stabilized by oleylamine ligands. We give evidence of charging effects in the weakly coupled one-dimensional (1D) nanowires, monitored by the temperature and the bias voltage. At low temperature, in the Coulomb blockade regime, the current flow reveals an original cooperative multi-hopping process between 1D-segments of Au-NWs, minimising the charging energy cost. Above the Coulomb blockade threshold voltage and at high temperature, the charge transport evolves into a sequential tunneling regime between the nearestnanowires. Our analysis shows that the effective length of the Au-NWs inside the bundle is similar to the 1D localisation length of the electronic wave function (of the order of 120 nm ± 20 nm), but almost two orders of magnitude larger than the diameter of the nanowire. This result confirms the high structural quality of the Au-NW segments.

Domaines: Supraconductivité [cond-mat.supr-con]

A. Loubat, Walter Escoffier, Lise-Marie Lacroix, G. Viau, Reasmey Phary Tan, et al.. Cotunneling transport in ultra-narrow gold nanowire bundles. Nano Research, 2013, 6, pp.644-651. ⟨10.1007/s12274-013-0340-8⟩. ⟨hal-00873476⟩