December 23, 2013

Resistance makes waves

There is a growing understanding of the conditions required for superconductivity and how it can be achieved at realistic temperatures

Even physics can give pointers for energy saving. An international team working together with the Centre for Quantum Materials, run by the Max Planck Society in conjunction with the University of British Columbia (Canada), is now in a position to provide materials scientists with tips for the development of high-temperature superconductors, in a bid to make them earn their name. The term is currently used to describe materials including ceramic cuprates, which lose their electrical resistance at significantly higher temperatures than conventional superconductors, but still well below the freezing point of water. In two complementary studies, the physicists have now established that superconductivity in cuprates collapses at a maximum of minus 135 degrees Celsius due to the formation of charge-density waves. These periodic fluctuations in the distribution of the electrical charges destroy superconductivity. Consequently, in order to find superconductors that drop to zero resistance at realistic temperatures, materials scientists must search for substances that are not subject to charge-density waves.