Abstract
The single-layered ruthenate Sr2RuO4 is one of the most enigmatic unconventional superconductors. While for many years it was thought to be the best candidate for a chiral p-wave superconducting ground state, desirable for topological quantum computations, recent experiments suggest a singlet state, ruling out the original p-wave scenario. The superconductivity as well as the properties of the multi-layered compounds of the ruthenate perovskites are strongly influenced by a van Hove singularity in proximity of the Fermi energy. Tiny structural distortions move the van Hove singularity across the Fermi energy with dramatic consequences for the physical properties. Here, we determine the electronic structure of the van Hove singularity in the surface layer of Sr2RuO4 by quasi-particle interference imaging. We trace its dispersion and demonstrate from a model calculation accounting for the full vacuum overlap of the wave functions that its detection is facilitated through the octahedral rotations in the surface layer.
| Original language | English |
|---|---|
| Article number | 100 |
| Journal | npj Quantum Materials |
| Volume | 6 |
| Issue number | 1 |
| DOIs | |
| State | Published - Dec 2021 |
Funding
We acknowledge useful discussions with B.M. Andersen, J.C. Davis, E. Fradkin, S.A. Kivelson, V. Madhavan, A.W. Rost, and A. Rømer. P. J.H. was supported by the US Department of Energy under Grant no. DE-FG02-05ER46236. C.A.M. and P.W. acknowledge funding from EPSRC through EP/L015110/1 and EP/R031924/1, respectively, and L. C.R. from the Royal Commission for the Exhibition of 1851. A portion of this work (T.B. and X.K.) was conducted at the Center For Nanophase Materials Sciences, which is a US Department of Energy Office of Science User Facility. This research used resources of the Compute and Data Environment for Science (CADES) at the Oak Ridge National Laboratory, which is supported by the Office of Science of the U.S. Department of Energy under Contract no. DE-AC05-00OR22725. This manuscript has been authored by UT-Battelle, LLC under Contract No. DE-AC05-00OR22725 with the US Department of Energy. The United States Government retains and the publisher, by accepting the article for publication, acknowledges that the United States Government retains a non-exclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this manuscript, or allow others to do so, for United States Government purposes. The Department of Energy will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan (https://www.energy.gov/ downloads/doe-public-access-plan). Open Access funding enabled and organized by Projekt DEAL and Open Access Publishing Fund of Leipzig University.