NEW YORK, OCT. 1 -- Two new studies show superconducting materials can transmit electrical pulses lasting only a few trillionths of a second, suggesting they may make faster computer wiring and possibly telephone lines, scientists say.
Briefer pulses mean more signals can be sent per second, so the results show superconductors can carry very high volumes of information, said Gerard Mourou of the University of Rochester in New York.
However, superconductors would not be practical for such uses as high-volume telephone lines unless scientists can create materials that superconduct at room temperatures, he said.
Superconductors conduct electricity without resistance. Standard superconductors must be chilled well below minus 400 degrees Fahrenheit, an expensive process that has limited their usefulness.
But newly created superconductors work at higher temperatures, and scientists hope to achieve room-temperature superconductivity.
Mourou said pulses as brief as 10 trillionths or 15 trillionths of a second had been transmitted through a superconductor film chilled to around minus 405 degrees Fahrenheit, well below its maximum superconducting temperature.
Alex Malozemoff of the IBM Research Center in Yorktown Heights said today an IBM team had transmitted pulses of two trillionths of a second through a combination of a superconductor and aluminum, chilled to minus 321 degrees Fahrenheit.
In both experiments, the pulses traveled about a fifth of an inch without being absorbed or significantly distorted, the scientists said. Both experiments also used a typical recipe for the new wave of superconductors, which includes yttrium, barium, copper and oxygen.
The superconductor in the experiment by Mourou and colleagues was made by Robert Buhrman and colleagues at Cornell University in Ithaca.
Standard superconductors had already been shown to carry extremely brief electrical pulses without distortion, Mourou said Wednesday in a telephone interview.
Mourou said the new results show superconductors can transmit more data per second than fiber optics systems, which are used in some telephone lines. Optical systems slow down when they convert electronic pulses to light for transmission, and back to electronic pulses again at the other end of the line, he said.
But Paul Henry, director of the communications systems research laboratory at AT&T Bell Laboratories, said a superconducting telephone line would face the same sort of slowdown in electronic signal-processing devices at each end.
Mourou insisted that a superconducting line would still be faster.