High-temperature superconductors: underlying physics and applications

TL;DR

This paper reviews the fundamental physics and diverse applications of superconductors, highlighting the breakthrough of high-temperature cuprates and exploring future prospects including room-temperature superconductivity.

Contribution

It provides a comprehensive overview of both conventional and high-temperature superconductors, emphasizing recent discoveries and future challenges in the field.

Findings

High-temperature superconductors reach up to 135 K.

Superconductors have broad applications from electronics to power systems.

Future research aims at achieving room-temperature superconductivity.

Abstract

Superconductivity was discovered in 1911 by Kamerlingh Onnes and Holst in mercury at the temperature of liquid helium (4.2 K). It took almost 50 years until in 1957 a microscopic theory of superconductivity, the so-called BCS theory, was developed. Since the discovery a number of superconducting materials were found with transition temperatures up to 23 K. A breakthrough in the field happened in 1986 when Bednorz and M\"uller discovered a new class of superconductors, the so-called cuprate high-temperature superconductors with transition temperatures as high as 135 K. This surprising discovery initiated new efforts with respect to fundamental physics, material science, and technological applications. In this brief review the basic physics of the conventional low-temperature superconductors as well as of the high-temperature superconductors are presented with a brief introduction to applications exemplified from high-power to low-power electronic devices. Finally, a short outlook and future challenges are presented, finished with possible imaginations for applications of room-temperature superconductivity.