Supraleittisiä

Supraleittisiä refers to materials that exhibit superconductivity. Superconductivity is a quantum mechanical phenomenon observed in certain materials when they are cooled below a critical temperature. In this state, the material has zero electrical resistance, meaning that electric current can flow through it indefinitely without any energy loss. Additionally, superconductors expel magnetic fields from their interior, a property known as the Meissner effect.

The discovery of superconductivity dates back to 1911 by Heike Kamerlingh Onnes. Initially, superconductivity was observed only in elemental metals at very low temperatures, close to absolute zero. The development of high-temperature superconductors in the late 1980s, which operate at significantly higher, albeit still cold, temperatures, has expanded the potential applications of this technology.

The mechanisms behind superconductivity can be broadly categorized into two types. Conventional superconductors are explained by the Bardeen-Cooper-Schrieffer (BCS) theory, which describes how electrons form Cooper pairs mediated by lattice vibrations. Unconventional superconductors, particularly the high-temperature ones, are thought to involve more complex mechanisms that are still an active area of research.

Potential applications of superconductors are vast and include powerful electromagnets for MRI machines and particle accelerators, high-speed maglev trains, energy-efficient power transmission, and advanced computing. However, the need for cryogenic cooling remains a significant challenge for widespread adoption. Research continues to focus on discovering materials that superconduct at even higher temperatures, ideally at room temperature.