The Search for Nanoscale Materials that Superconduct

Clemson University is part of a five-year $3 million Air Force Office of Scientific Research award, along with the University of Texas at Dallas and Yale University, to search for nanoscale materials that superconduct to allow for efficient flow of a current.

Specifically, the team will explore carbon nanotube-based superconductors to develop composite wires that may eventually be used, among other things, to replace inefficient copper wiring in power lines that presently can lose up to a third of their energy as heat.

"In the superconducting state, the flow of charges does not experience resistance, so the current flow is very efficient," said Clemson University physics professor Apparao Rao. "The holy grail is to get these charges to move with similar efficiency at room temperature instead of at extremely cool temperatures."

At Clemson, Rao has used pulsed lasers to produce superconducting nanotubes that are thousands of times smaller than a strand of hair, also referred to as low-dimensional materials. The process developed in his labs yields carbon nanotubes that are doped with elemental boron, which enables the nanotubes to superconduct at low temperatures.

"We are very excited about this discovery since superconducting nanotubes are not only useful in several applications but also serve as an ideal candidate to explore the underpinning physics in low-dimensional materials, which has long been a challenge," said Rao. "Clemson's role in this research is to build on this success and experiment with nanotubes doped with other elements such as sulfur, nitrogen and phosphorous with a view toward fabricating doped nanotubes that superconduct without having to cool them to very low temperatures, which is the technology used today."

In partnership with UT Dallas and Yale, Rao says the bigger question to be addressed is the incorporation of Clemson's doped nanotubes into high-strength, lightweight superconducting wires for such uses as medical MRI imaging, efficient power lines and other Air Force applications.