High-temperature superconductors, also known as cuprates, are a class of materials that exhibit superconductivity at relatively high temperatures compared to traditional superconductors. This property makes them promising for various technological applications, as they can operate at higher temperatures, reducing the need for expensive cooling systems. However, the behavior of cuprates has been challenging to explain due to their unique properties.
The Hatsugai-Kohmoto (HK) Model
In a groundbreaking development, a team of theoretical physicists at the Institute for Condensed Matter Theory (ICMT) in the Department of Physics at the University of Illinois at Urbana-Champaign has solved a representative model of the cuprate problem, the 1992 Hatsugai-Kohmoto (HK) model of a doped Mott insulator. This achievement marks a significant milestone in understanding the behavior of high-temperature superconductors, which have been a mystery to physicists for decades.
Unlike traditional superconductors, cuprates are insulators at room temperature and transition to a superconducting phase at a much higher critical temperature. This behavior is not accounted for in the Bardeen-Cooper-Schrieffer (BCS) theory of superconductivity, which explains superconductivity in traditional superconductors.