Cross junctions of carbon nanotubes (CNTs) separated by thin oxide layers have been fabricated, in which the top CNT is used as a local gate to control the electron transport through the lower CNT. Coulomb oscillation was observed in the lower CNTs at low temperatures. The gating field from the upper CNTs is seen to modulate the band structure in the lower CNTs, producing double quantum dot systems. The ability to modulate the electronic structure of CNTs in such a way opens up many possibilities for future electronic and logical nanodevices.
Bibliographical noteFunding Information:
This work was supported by the Nano Systems Institute-National Core Research Center (NSI-NCRC) program of KOSEF, Korea, by the Swedish Strategic Research Foundation (SSF), Vetenskapsrådet, and by STINT (Stiftelsen för internationalisering av högre utbildning och forskning). The authors acknowledge the help of Sang Wook Lee in preparing the measurements.