Old Questions and New Results - Recent Advances in Superconductivity

The mechanism of high-temperature superconductivity remains a subject of research, although there is a fairly widespread view that it is not the classical Bardeen–Cooper–Schrieffer mechanism. One of the most active critics of the Bardeen–Cooper–Schrieffer theory is J. Hirsch, who also presents his hole superconductivity model as a theory that better describes this phenomenon. We review the current state and prospects of experimental confirmation of the hole theory of superconductivity and discuss the results of contemporary experimental and theoretical works related to issues identified as significant tests of the credibility of this theory.