Investigating the Pairing Symmetry in Uniaxially Strained Sr2RuO4 by 17O NMR Shifts

ORAL

Abstract

The unconventional superconductor and Fermi liquid Sr2RuO4 exhibits clear effects of electronic correlations associated with Hund’s Rule coupling. In the superconducting (SC) state, several experiments produced evidence for time reversal symmetry breaking, and nuclear magnetic resonance (NMR) Knight shift measurements were consistent with an equal-spin pairing triplet state. To that end, Sr2RuO4 is widely considered as a potential candidate for a chiral p-wave pairing with an order parameter of px ± ipy symmetry - a solid state analog to 3He-A.
Motivated by the recent observation of a strong peak in Tc across a strain-induced Lifshitz transition associated with a van Hove singularity, we studied the 17O NMR shifts in the SC state of Sr2RuO4. Our low-temperature experiments at high strain reveal a drop of spin susceptibility below Tc evidenced by unambiguous reduction of Knight shifts for the in-plane O sites. Most pronounced at the Lifshitz point, the loss of spin susceptibility on entering the SC state is reduced on lowering the strain, while no evidence for a phase transition between distinct SC states is observed.

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Presenters

  • Andrej Pustogow

    Department of Physics and Astronomy, University of California, Los Angeles, University of California, Los Angeles, 1. Physikalisches Institut, Universität Stuttgart

Authors

  • Andrej Pustogow

    Department of Physics and Astronomy, University of California, Los Angeles, University of California, Los Angeles, 1. Physikalisches Institut, Universität Stuttgart

  • Yongkang Luo

    Department of Physics and Astronomy, University of California, Los Angeles, University of California, Los Angeles

  • Aaron Chronister

    University of California, Los Angeles

  • Yue-Shun Su

    Department of Physics and Astronomy, University of California, Los Angeles, University of California, Los Angeles

  • Naoki Kikugawa

    Max Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany, National Institute for Material Science, Tsukuba, Ibaraki, National Institute for Materials Science, Tsukuba, National Institute for Materials Science, Quantum Transport Properties Group, National Institute for Materials Science (NIMS), Tsukuba 305-0003, Japan, National Institute for Material Science

  • Dmitry Sokolov

    Max Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany, Max-Planck-Institut for Chemical Physics of Solids, Max Planck Institute for Chemical Physics of Solids

  • Fabian Jerzembeck

    Max Planck Institute for Chemical Physics of Solids

  • Andrew Mackenzie

    Max-Planck-Institute for Chemical Physics of Solids, Max Planck Institute for Chemical Physics of Solids, Max Planck Institute for Chemical Physics of Solids, Dresden,Germany, Max Planck Institute for Chemical Physics of Solids, Dresden, Germany, Max Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany, Max-Planck-Institut for Chemical Physics of Solids, Physics of Quantum Materials, Max Planck Institute of Chemical Physics of Solids

  • Clifford Hicks

    Max Planck Institute for Chemical Physics of Solids

  • Eric Bauer

    Los Alamos National Laboratory, Los Alamos, NM 87545, USA, Los Alamos National Laboratory, MPA-CMMS, Los Alamos National Laboratory, Los Alamos, USA, MPA-CMMS, Los Alamos National Laboratory, Los Alamos National Laboratory, Los Alamos, New Mexico, USA, Los Alamos National Labs

  • Stuart E Brown

    Univ of California - Los Angeles, Department of Physics and Astronomy, University of California, Los Angeles, University of California, Los Angeles