Magic angle of Sr 2 RuO 4 : Optimizing correlation-driven superconductivity

Physical Review Research, vol. 6

Abstract

Understanding of unconventional superconductivity is crucial for engineering materials with specific order parameters or elevated superconducting transition temperatures. However, for many materials, the pairing mechanism and symmetry of the order parameter remain unclear: reliable and efficient methods of predicting the order parameter and its response to tuning parameters are lacking. Here, we investigate the response of superconductivity in Sr 2 RuO 4 to structural distortions via the random phase approximation (RPA) and functional renormalization group (FRG), starting from realistic models of the electronic structure. Our results suggest that RPA misses the interplay of competing fluctuation channels. FRG reproduces key experimental findings. We predict a magic octahedral rotation angle, maximizing the superconducting T c and a dominant d x 2 − y 2 pairing symmetry. To enable experimental verification, we provide calculations of the phase-referenced Bogoliubov Quasiparticle Interference imaging. Our work demonstrates a designer approach to tuning unconventional superconductivity with relevance and applicability for a wide range of quantum materials. Published by the American Physical Society 2024

Authors 11

1. Jonas B. Profe Aachen

   Goethe University Frankfurt · RWTH Aachen University

   Affiliation as printed

   Goethe University Frankfurt

   RWTH Aachen University

2. Luke C. Rhodes

   University of St Andrews

   Affiliation as printed

   University of St Andrews

   SUPA, School of Physics and Astronomy, University of St Andrews, North Haugh, St Andrews, KY16 9SS, United Kingdom

3. Matteo Dürrnagel

   University of Würzburg · ETH Zurich

   Affiliation as printed

   ETH Zürich

   University of Würzburg

4. Rebecca Bisset

   University of St Andrews

   Affiliation as printed

   University of St Andrews

   SUPA, School of Physics and Astronomy, University of St Andrews, North Haugh, St Andrews, KY16 9SS, United Kingdom

5. Carolina A. Marques

   University of Zurich

   Affiliation as printed

   Universität Zürich

6. Shun Chi

   University of British Columbia

   Affiliation as printed

   University of British Columbia

   Department of Physics and Astronomy, University of British Columbia, Vancouver BC, Canada V6T 1Z1

   Stewart Blusson Quantum Matter Institute, University of British Columbia, Vancouver BC, Canada V6T 1Z4

7. Tilman Schwemmer

   University of Würzburg

   Affiliation as printed

   University of Würzburg

8. Ronny Thomale

   University of Würzburg

   Affiliation as printed

   University of Würzburg

9. Dante Marvin Kennes Aachen

   Center for Free-Electron Laser Science · Max Planck Institute for the Structure and Dynamics of Matter · RWTH Aachen University

   Affiliation as printed

   Max Planck Institute for the Structure and Dynamics of Matter

   RWTH Aachen University

   Max Planck Institute for the Structure and Dynamics of Matter, Center for Free Electron Laser Science, 22761 Hamburg, Germany

10. C. Hooley

    Max Planck Institute for the Physics of Complex Systems

    Affiliation as printed

    Max Planck Institute for the Physics of Complex Systems

11. Peter Wahl

    University of Bonn · University of St Andrews

    Affiliation as printed

    University of St Andrews

    Universität Bonn

    SUPA, School of Physics and Astronomy, University of St Andrews, North Haugh, St Andrews, KY16 9SS, United Kingdom