Superconductors are making a come-back to the EPSRC UK Graduate Summer School in Condensed Matter “Theory Physics by the Lake”. I copy below the summary of the short course on the subject I will be offering there. For information on the other courses and on the workshop generally, go to the official Physics by the Lake webpages.
USC: Unconventional Superconductivity
Part of the EPSRC UK Graduate Summer School in Condensed Matter Theory
“Physics by the Lake”
From ultra-fast trains to ultra-efficient supercomputers, applications of superconductivity keep gathering pace and promise to transform our world. On the other hand, the theory of superconductivity due to Bardeen, Cooper and Schrieffer, developed the 1950’s and based on the idea of isotropic, singlet, phonon-mediated electron-electron pairing, can only fully explain what we term “conventional superconductors”. The rest –which include the Copper-based and Iron-based high-temperature superconductors as well as many other exotic materials– deviate from BCS theory in some (or sometimes many) ways. In this course you will find out what we know and, more importantly, what we don’t know about the many, and actually quite diverse, classes of unconventional superconductors. We will touch on exotic pairing (where the electron pairs have exotic structures, with non-trivial topologies or breaking additional symmetries), unconventional pairing mechanisms (i.e. not phonons), competing (sometimes “hidden”) order parameters, and more. We will take BCS theory as a bedrock and discuss whether, and how, the theory has to be extended to account for each of the new features.