Johns Hopkins University scientists have developed a new method of maintaining resistance-free current. The development will improve the performance of superconducting wires used in MRI medical scanners and other technologies.
Vortices, a collection of electrons into tornado-like formations, skitter from side to side across a conducting material, spoiling the zero-resistance current. The researchers constrained electron vortices by trapping them within extremely short, ultra-thin nanowires.
To overcome the difficulty of "pinning" the vortices to impurities in the conducting material, the Johns Hopkins scientists made a superconducting sample that consists mostly of edges: a very narrow aluminum nanowire.
The flat strips are about one-billionth as wide as a human hair, and about 50 to 100 times longer than their width. Each nanowire forms a one-way highway that allows pairs of electrons to zip ahead at a supercurrent pace.
Future computers or other devices may someday use vortices instead of electrical charges to transmit information.
