Self-assembled chains of graphitized carbon nanoparticles
  We report a technique which allows self-assembly of conducting nanoparticles into long continuous chains. Transport properties of such chains have been studied at low temperatures. At low bias voltages, the charges are pinned and the chain resistance is exponentially high. Above a certain threshold ($V_{T}$), the system enters a conducting state. The threshold voltage is much bigger than the Coulomb gap voltage for a single particle and decreases linearly with increasing temperature. A sharp threshold was observed up to about 77 K. Such chains may be used as switchable links in Coulomb charge memories. 
A. Bezryadin, R.M. Westervelt, and M. Tinkham