University of Bristol physicists identify mechanism for high-temperature superconductivity

Physicists at the University of Bristol, as part of an international research team, have identified electron spin fluctuations as the primary mechanism driving high-temperature superconductivity in copper-oxide materials. The study, published in Nature Physics, focuses on electron-doped cuprates, specifically lanthanum cerium copper oxide (La 2− x Ce x CuO 4).

By fabricating a specialized thin-film sample with a smooth gradient of critical temperature (Tc), researchers were able to map the dominant source of electrical resistance. They discovered a direct link between resistance and the critical temperature, noting a “highly anisotropic inelastic component” to electron scattering that diminishes as doping increases.

This finding suggests that low-energy spin fluctuations act as the pairing glue for electrons in these materials. The research also highlights a distinction between electron-doped and hole-doped cuprates, indicating that while spin fluctuations are a key component, additional factors may be required to explain the higher critical temperatures observed in hole-doped systems.