Formation of single quantum dot in single-walled carbon nanotube channel using focused-ion-beam technique

The authors fabricated a single quantum dot in a single-walled carbon nanotube (SWCNT) channel using focused-ion-beam techniques. They used this technique to form two tunnel barriers, constituting a single quantum dot, by introducing two damaged regions with a separation of 50 nm into a SWCNT channel. Electrical properties revealed that source-drain current oscillation as a function of gate voltage was clearly observed at room temperature, resulting from the Coulomb blockade effect. Charging energy of the single quantum dot in the SWCNT channel was estimated to be 255 meV, which is approximately ten times larger than thermal energy at room temperature. (c) 2007 American Institute of Physics.