Superconductors - Theoretical basis

Superconductivity is a remarkable phenomenon, discovered as early as 1911, whose main property is to render the material perfectly and brutally electrically conductive below a so-called critical temperature. However, we had to wait until the 1960s to see the first real applications for superconductors, which are still limited to certain niches. The discovery of superconducting oxides with critical temperatures in excess of 80 K, hence the term "high-temperature superconductors", has enabled the commercial development of superconducting applications. Many other materials exhibit superconductivity (see Box A), so this phenomenon is not uncommon.

The superconducting state differs from the normal state in many diverse properties, which will be presented in this article. Applications will be presented in the articles :

• Superconductors – Wire structure and behavior ;

• Superconductors – Environment and applications .