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Latest news on superconductors, a material that has no electrical resistance and does not allow magnetic fields to penetrate it when it is cooled below a certain critical temperature. An electric current in a superconductor can persist indefinitely without any power source.

Superconductivity was discovered in 1911 by Dutch physicist Heike Kamerlingh Onnes, who observed that the resistance of mercury vanished when he cooled it to below 4.2 K.

Superconductors are classified into two types: Type I and Type II. Type I superconductors have a single critical field, above which all superconductivity is lost and below which the magnetic field is completely expelled from the superconductor. Type II superconductors have two critical fields, between which they allow partial penetration of the magnetic field through isolated points called vortices.

Superconductors have many applications, such as MRI machines, maglev trains, particle accelerators, quantum computers, and power transmission.

Superconductivity is a quantum phenomenon that cannot be explained by classical physics. It is characterized by the Meissner effect, the complete ejection of magnetic field lines from the interior of the superconductor during its transitions into the superconducting state.

The theory of superconductivity was developed by Lev Landau and Vitaly Ginzburg in 1950, and later by John Bardeen, Leon Cooper, and Robert Schrieffer in 1957. The latter theory is known as the BCS theory and explains how pairs of electrons (called Cooper pairs) form in a superconductor and move without resistance.

The critical temperature of a superconductor depends on the material and its composition. Most superconductors have very low critical temperatures, close to absolute zero. However, in 1986, it was discovered that some ceramic materials have critical temperatures above 90 K, which are called high-temperature superconductors. These materials are still not well understood and are the subject of ongoing research.