Universal Electromagnetic Properties of Strongly-coupled Electron-phonon Superconductors

Explore the fascinating world of high-temperature superconductors in this 1-hour 40-minute lecture by Joshuah T. Heath from Dartmouth College. Delve into the exotic normal states of these materials and their ongoing significance in scientific research. Examine Homes law, which proposes a linear relationship between superconducting ground-state properties and normal-phase DC conductivity. Discover how this law applies to conventional BCS superconductors in the dirty limit and its empirical nature in other contexts. Follow Heath's theoretical and numerical work on universal scaling relations in electron-phonon superconductors described by Eliashberg theory. Learn how Homes scaling is independent of both high-Tc pairing mechanisms and dirty BCS-like physics, instead resulting from non-Galilean invariant interactions. Investigate the asymptotically strong limit of Eliashberg equations and their reduction to a universal theory described by an Einstein spectrum. Gain insights into the universal statements about scaling relations and electromagnetic properties of strongly coupled electron-phonon superconductors. Understand how Homes scaling emerges as a fundamental result across a wide range of superconducting compounds, challenging the conventional definition of "conventional" superconductivity.