The superconductivity of Sr2RuO4 under c-axis uniaxial stress

• DOI: 10.1038/s41467-022-32177-4
• Publication Date: 2022-08-06T13:02:57Z
• Authors: Fabian Jerzembeck; Henrik S. Røising; Alexander Steppke; Helge Rosner; Dmitry A. Sokolov; Naoki Kikugawa; Thomas Scaffidi; Steven H. Simon; Andrew P. Mackenzie; Clifford W. Hicks
• Keywords: Science; Condensed Matter - Superconductivity; Q; 500; FOS: Physical sciences; DAS; 530; 01 natural sciences; Article; Superconductivity (cond-mat.supr-con); QC Physics; 0103 physical sciences; QC

AbstractApplying in-plane uniaxial pressure to strongly correlated low-dimensional systems has been shown to tune the electronic structure dramatically. For example, the unconventional superconductor Sr2RuO4 can be tuned through a single Van Hove point, resulting in strong enhancement of both Tc and Hc2. Out-of-plane (c axis) uniaxial pressure is expected to tune the quasi-two-dimensional structure even more strongly, by pushing it towards two Van Hove points simultaneously. Here, we achieve a record uniaxial stress of 3.2 GPa along the c axis of Sr2RuO4. Hc2 increases, as expected for increasing density of states, but unexpectedly Tc falls. As a first attempt to explain this result, we present three-dimensional calculations in the weak interaction limit. We find that within the weak-coupling framework there is no single order parameter that can account for the contrasting effects of in-plane versus c-axis uniaxial stress, which makes this new result a strong constraint on theories of the superconductivity of Sr2RuO4.