16. Bardeen, Cooper, and Schrieffer Develop Theory of Superconductivity (1957)

Nearly half a century after superconductivity was discovered, Bardeen, Cooper, and Schrieffer (BCS) provide a theory for the phenomenon in terms of electrons that pair up and condense into a single quantum state. BCS theory has been applied not only to problems in condensed matter, but also in particle and nuclear physics.

What is BCS Theory:

In 1986, high-temperature superconductivity was discovered in some materials at temperatures up to about 130 K, considerably above the previous limit of about 30 K. It is believed that BCS theory alone cannot explain this phenomenon and that other effects are in play. These effects are still not yet fully understood; it is possible that they even control superconductivity at low temperatures for some materials.

So new theory needs to be made for High-Temperature superconductivity: