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Strain-stabilized superconductivity in RuO<sub>2</sub>

ORAL

Abstract

The rational control of superconductivity and the possibility of deterministically enhancing the superconducting transition temperature (Tc) by design, rather than by serendipity, has been an elusive and long sought-after goal in solid-state physics. Here, we report the first instance of transmuting a normal metal into a superconductor through the application of epitaxial strain. We demonstrate that synthesizing RuO2 thin films on TiO2(110) substrates stabilizes superconductivity under strain, having Tcs up to 2 K; by contrast, RuO2 thin films grown on TiO2(101) substrates are non-superconducting down to the lowest measured temperatures (Tc < 0.4 K), consistent with the behavior of bulk RuO2. Using a comprehensive combination of characterization techniques—including electrical transport, x-ray diffraction, scanning transmission electron microscopy, angle-resolved photoemission spectroscopy, and density functional theory—we reveal the primary electronic mechanism underlying this strain-stabilized superconductivity: the anisotropic strains redistribute the carriers amongst the manifold of 4d states near the Fermi level (EF), partially depopulating flat bands with d|| orbital character, and thereby increase the density of states at EF.

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Presenters

  • Jacob Ruf

    Cornell University, Laboratory of Atomic and Solid State Physics, Department of Physics, Kavli Institute at Cornell for Nanoscale Science, Cornell University

Authors

  • Jacob Ruf

    Cornell University, Laboratory of Atomic and Solid State Physics, Department of Physics, Kavli Institute at Cornell for Nanoscale Science, Cornell University

  • Hanjong Paik

    Cornell University, Platform for the Accelerated Realization, Analysis, and Discovery of Interface Materials (PARADIM), Cornell University, PARADIM, Cornell University, Platform for the Accelerated Realization, Analysis, & Discovery of Interface Materials (PARADIM), Cornell University

  • Nathaniel Schreiber

    Cornell University

  • Hari Nair

    Cornell University, Department of Materials Science and Engineering, Kavli Institute at Cornell for Nanoscale Science, Cornell University

  • Ludi Miao

    Cornell University, Laboratory of Atomic and Solid State Physics, Department of Physics, Kavli Institute at Cornell for Nanoscale Science, Cornell University, Laboratory of Atomic and Solid State Physics, Cornell University

  • Jason Kawasaki

    Materials Science and Engineering, University of Wisconsin Madison, Materials Science, University of Wisconsin-Madison, Materials Science and Engineering, University of Wisconsin-Madison, Cornell University

  • Jocienne Nelson

    Department of Physics, Cornell University, Cornell University, Cornell University

  • Brendan Faeth

    Cornell University

  • Yonghun Lee

    Cornell University

  • Berit Goodge

    Cornell University, Applied and Engineering Physics, Cornell University

  • Betul Pamuk

    Cornell University

  • Craig Fennie

    School of Applied and Engineering Physics, Cornel University, Cornell University

  • Lena Fitting Kourkoutis

    Cornell University, Applied and Engineering Physics, Cornell University, Kavli Institute at Cornell for Nanoscale Science

  • Darrell Schlom

    Cornell University, Department of Materials Science and Engineering, Cornell University, Department of Materials Science and Engineering, Kavli Institute at Cornell for Nanoscale Science, Cornell University, Materials Science and Engineering, Cornell University, Kavli Institute at Cornell for Nanoscale Science, Ithaca, New York 14853, USA, Platform for the Accelerated Realization, Analysis, & Discovery of Interface Materials (PARADIM), Cornell University

  • Kyle M Shen

    Cornell University, Department of Physics, Cornell University, Cornell University, Department of Physics, Laboratory of Atomic and Solid State Physics, Cornell University, Laboratory of Atomic and Solid State Physics, Department of Physics, Kavli Institute at Cornell for Nanoscale Science, Cornell University