Candidate for Second Dome of Superconductivity in a Cuprate at High Pressures

Evidence is growing that a second dome of higher-T_c superconductivity can be accessed in cuprates by pushing the Cu valence towards 3⁺, either by replacing La by Ba or Sr in La₂CuO₄ or by using high pressure to overdope Bi cuprates. While Sr₂CuO₄ and Ba₂CuO₄ are found to superconduct at considerably higher temperatures than La₂CuO₄, they are quite difficult to analyze as they are strongly oxygen-deficient and there is ongoing debate about which phase is superconducting and where the vacancies are. Here we use ab initio studies to reveal that pressure can turn a related cuprate into an ideal candidate for second-dome superconductivity, displaying the predicted signature structure of strongly hybridized d-d orbitals.