Unconventional Superconductor - History and Progress

History and Progress

  • April 1986 - The term high-temperature superconductor was first used to designate the new family of cuprate-perovskite ceramic materials discovered by Johannes Georg Bednorz and Karl Alexander Müller, for which they won the Nobel Prize in Physics the following year. Their discovery of the first high-temperature superconductor, LaBaCuO, with a transition temperature of 35 K, generated great excitement.
  • LSCO (La2-xSrxCuO2) discovered the same year.
  • January 1987 - YBCO was discovered to have a Tc of 90 K.
  • 1988 - BSCCO discovered with Tc up to 107 K, and TBCCO (T=thallium) discovered to have Tc of 125 K.
  • As of 2009, the highest-temperature superconductor (at ambient pressure) is mercury barium calcium copper oxide (HgBa2Ca2Cu3Ox), at 138 K and is held by a cuprate-perovskite material, possibly 164 K under high pressure.
  • Recently, other unconventional superconductors, not based on cuprate structure, have been discovered. Some have unusually high values of the critical temperature, Tc, and hence they are sometimes also called high-temperature superconductors.

After more than twenty years of intensive research the origin of high-temperature superconductivity is still not clear, but it seems that instead of electron-phonon attraction mechanisms, as in conventional superconductivity, one is dealing with genuine electronic mechanisms (e.g. by antiferromagnetic correlations), and instead of s-wave pairing, d-waves are substantial.

One goal of all this research is room-temperature superconductivity.

Read more about this topic:  Unconventional Superconductor

Famous quotes containing the words history and, history and/or progress:

    The principle that human nature, in its psychological aspects, is nothing more than a product of history and given social relations removes all barriers to coercion and manipulation by the powerful.
    Noam Chomsky (b. 1928)

    You that would judge me do not judge alone
    This book or that, come to this hallowed place
    Where my friends’ portraits hang and look thereon;
    Ireland’s history in their lineaments trace;
    Think where man’s glory most begins and ends
    And say my glory was I had such friends.
    William Butler Yeats (1865–1939)

    In fast-moving, progress-conscious America, the consumer expects to be dizzied by progress. If he could completely understand advertising jargon he would be badly disappointed. The half-intelligibility which we expect, or even hope, to find in the latest product language personally reassures each of us that progress is being made: that the pace exceeds our ability to follow.
    Daniel J. Boorstin (b. 1914)