Nanotechnology is the way to go, scientists say. As science evolves towards smaller devices, single electron devices are considered one way for computing and other electronic applications and also provide a way to better understand the quantum state in a controllable manner.

Researches in Korea might have already found a prototype for such a single electron device. Their work explains how a quantum dot device could be fabricated as a carbon nanotube with a double wall, by studying some of the unexplored electronic structures of the nanotube technology.

A quantum dot is made from a semiconductor nanostructure that narrows the motion of the conduction band electrons, valence band, or excitons. The confinement can be produced by electrostatic potentials, the presence of an interface between the different semiconductor materials or a different combination of these. A quantum dot has a discrete quantize energy.

There are a lot of ways to create quantum dots, one way is by using carbon nanotubes, the chosen material by the scientists of Korea University, because it is small in size and shows highly symmetric structures of electronic transport. Instead of using a single nanotube wall, the researchers chose to explore the properties of a double walled nanotube.

The cylindrical symmetry of the carbon nanotubes and the strong electron-electron interaction make each wall in a four-diamond structure. Until now scientists could only observe this perfect symmetry in single-wall carbon, nanotubes. Mahn-Soo Choi, a scientist at Korea University, speculated that this might have been so because of the presence of defects in multi-walled carbon nanotubes.

During the experiments scientists observed that the inner and outer walls of the nanotube interact with each other and by using a method to control the number of electrons in the carbon nanotube, they have been able to test the electrical capabilities of the material. The voltage that was applied to the nanotube was changing the patterns on the walls. This effect is generated when the pattern of the outer wall follows intently the change, but the inner wall drags behind.

The experiment also provided new easier ways to fabricate quantum dots into a nanostructure electric circuit, which could lead to a single electron tunneling device. This technology could prove even more useful in the study of the quantum mechanical state of the electrons, but for now researchers have only begun the work which could lead to quantum engineering in single electron devices.