Jerzembeck Fabian, Røising Henrik S, Steppke Alexander, Rosner Helge, Sokolov Dmitry A, Kikugawa Naoki, Scaffidi Thomas, Simon Steven H, Mackenzie Andrew P, Hicks Clifford W
Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Str 40, 01187, Dresden, Germany.
Nordita, KTH Royal Institute of Technology and Stockholm University, Hannes Alfvéns väg 12, SE-106 91, Stockholm, Sweden.
Nat Commun. 2022 Aug 6;13(1):4596. doi: 10.1038/s41467-022-32177-4.
Applying in-plane uniaxial pressure to strongly correlated low-dimensional systems has been shown to tune the electronic structure dramatically. For example, the unconventional superconductor SrRuO can be tuned through a single Van Hove point, resulting in strong enhancement of both T and H. 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 SrRuO. H increases, as expected for increasing density of states, but unexpectedly T 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 SrRuO.
已证明，对强关联低维系统施加面内单轴压力会极大地调整其电子结构。例如，非常规超导体SrRuO可通过单个范霍夫点进行调整，从而使Tc和Hc都得到显著增强。预计面外（c轴）单轴压力会通过同时将准二维结构推向两个范霍夫点，从而更强烈地调整该结构。在此，我们在SrRuO的c轴方向上实现了3.2 GPa的创纪录单轴应力。正如态密度增加所预期的那样，Hc增加，但出乎意料的是Tc下降。作为解释这一结果的首次尝试，我们在弱相互作用极限下进行了三维计算。我们发现在弱耦合框架内，没有单一的序参量能够解释面内与c轴单轴应力的对比效应，这使得这一新结果对SrRuO超导理论构成了强有力的约束。
