A material that has little resistance to the flow of electricity. Traditional superconductors operate at absolute zero (-459.67 degrees Fahrenheit; -273.15 degrees Celsius). Experiments in the 1980s raised the temperature to -321 degrees Fahrenheit. By the late 1990s, superconductivity was demonstrated at -164 degrees Fahrenheit.
The major use for superconductors, made of alloys of niobium, is for high-powered magnets in medical imaging machines and particle accelerators. The magnets are cooled with liquid helium or liquid nitrogen. If superconductors can ever be made to work at reasonable temperatures, they will have a dramatic impact on the future of computing as well. In the meantime, the extra cost and bulk required to cool the circuits makes superconductive computers too expensive to commercialize. See Josephson junction