Nanotech Fine-Tuning
By Mark K. Anderson "If we're going to use nanotubes for any application, we're hoping that they'll one day replace not only wires but also be a sort of template for molecular scale electronics," said Ali Yazdani of the University of Illinois.
Yazdani is one of eight co-authors on the paper that first studied the electronic properties of these stuffed nanotubes. The paper will appear in an upcoming issue of Science and now appears on the journal's Science Express website.
"In a transistor, you want to modulate the electronic properties to control or gate the flow of electrons through it," Yazdani said. "That's the basic idea behind an electronic device."
Yazdani's device is called a nanotube "peapod" -- whose "peas" are typically the spherical C60 molecule, also known as buckminsterfullerene or buckyballs. By encapsulating C60 within a nanotube, Yazdani's team found that the electronic properties of the system varied from semiconductor to conductor to insulator, depending on the peas' positions.
They note that, if the peas are spaced periodically, quantum wave resonances of the electrons traveling through the system can also be tuned. This could, in turn, open the door to using the peapod as a medium for quantum computations.
"People talk about using quantum dots for quantum computations," Yazdani said. "A C60 molecule is a small dot ... and understanding these (peapod) structures may give us a clue how to engineer these quantum dot-like states."
Yazdani,2