What have we learned from high-pressure experiments on Cu-oxide and Fe-based superconductors?

Abstract

High-pressure experiments have made many important contributions to the field of superconductivity, including studies on the Cu-oxide and Fe-based high-temperature superconductors (HTS). However, for detailed quantitative understanding, the nature of the high-pressure environment acting on the sample must be well defined, a requirement often not met. Since HTS are quasi-2D, all properties are anisotropic. As a result, only a combination of fully hydrostatic and uniaxial pressure experiments are capable of providing the detailed information required. Unfortunately, very few such experiments have been carried out. For both Cu-oxide and Fe-based HTS at optimal doping, Tc is found to be enhanced by either increasing the separation of the superconducting planes or decreasing their area. Future experiments will extend such hydrostatic/uniaxial studies over the entire doping range. © Published under licence by IOP Publishing Ltd.