Superconductivity in High-Temperature Materials

Superconductivity, the complete loss of electrical resistance and expulsion of magnetic fields in certain materials below a critical temperature, remains one of the most fascinating quantum phenomena in condensed matter physics. Since its discovery in 1911 by Heike Kamerlingh Onnes, the study of superconductivity has grown into a multidisciplinary field connecting physics, materials science, and engineering. The development of the Bardeen–Cooper–Schrieffer (BCS) theory in 1957 provided a microscopic explanation for conventional superconductors. However, the discovery of high-temperature superconductors (HTS) in 1986 challenged existing theories and opened a new chapter in physics. These materials, especially copper-oxide (cuprate) superconductors, exhibit superconductivity at temperatures far above those predicted by BCS theory, in some cases even above the boiling point of liquid nitrogen (77 K).