Thoughts on the influence of Alex Mueller on high magnetic field technology

Abstract

I briefly summarize some of the impacts that Alex Mueller's drive to discover superconductivity in low carrier density oxides has had on high magnetic field technology, especially on the desire to use the cuprate superconductors to generate magnetic fields now almost twice those possible with the Nb-based low temperature superconductors. There were some important lessons for applications of any new exotic temperature superconductor that had to be learned before the Bednorz and Mueller discovery could really impact applications. Above all is the lesson that a high transition temperature is no guarantee of applications unless conductors with high current density can be manufactured. Recent reports and hopes for an ambient pressure room temperature superconductor remind us that the hopes for pervasive superconducting technologies germinated with the discovery of superconductivity in LaBaCuO and went truly ballistic following the discovery of YBa2Cu3O7-δ (YBCO) with a 92 K transition temperature. Now that magnets made out of rare earth alloys of YBCO (REBCO) have entered routine service in NMR labs and prototype magnets made with REBCO appear ready to enable compact fusion reactors, we can finally say that Bednorz and Mueller's magnificent scientific achievement is having real world applications impact too.