Constraints on the superconducting state of Sr${}_2$RuO${}_4$ from elastocaloric measurements

Abstract

Strontium ruthenate Sr${}_2$RuO${}_4$ is an unconventional superconductor whose pairing symmetry has not been fully clarified, despite more than two decades of intensive research. Recent NMR Knight shift experiments have rekindled the Sr${}_2$RuO${}_4$ pairing debate by giving strong evidence against all odd-parity pairing states, including chiral $p$-wave pairing that was for a long time the leading pairing candidate. Here, we exclude additional pairing states by analyzing recent elastocaloric measurements [YS. Li et al., Nature 607, 276--280 (2022)]. To be able to explain the elastocaloric experiment, we find that unconventional even-parity pairings must include either large $d_{x^2-y^2}$-wave or large $\{d_{xz}\mid d_{yz}\}$-wave admixtures, where the latter possibility arises because of the body-centered point group symmetry. These $\{d_{xz}\mid d_{yz}\}$-wave admixtures take the form of distinctively body-centered-periodic harmonics that have horizontal line nodes. Hence $g_{xy(x^2-y^2)}$-wave and $d_{xy}$-wave pairings are excluded as possible dominant even pairing states.

22 pages, 8 figures

References in corpus (22)

• High Resolution Polar Kerr Effect Measurements of Sr2RuO4: Evidence for Broken Time Reversal Symmetry in the Superconducting State
• Chiral P-Wave Order in Sr_2RuO_4
• Observation of half-height magnetization steps in Sr2RuO4
• First-Order Superconducting Transition of Sr2RuO4
• Elastocaloric determination of the phase diagram of Sr${}_2$RuO${}_4$
• High sensitivity heat capacity measurements on Sr2RuO4 under uniaxial pressure
• Sharp magnetization jump at the first-order superconducting transition in Sr2RuO4
• Nodeless spin triplet superconducting gap in Sr2RuO4
• Little-Parks oscillations with half-quantum fluxoid features in Sr2RuO4 micro rings
• Specific-heat evidence of the first-order superconducting transition in Sr2RuO4
• Higher-Tc Superconducting Phase in Sr2RuO4 Induced by In-Plane Uniaxial Pressure
• Anisotropic spin fluctuations in Sr${}_2$RuO${}_4$: role of spin-orbit coupling and induced strain
• Superconductivity in Correlated Multi-Orbital Systems with Spin-Orbit Coupling: Coexistence of Even- and Odd-Frequency Pairing and the Case of Strontium Ruthenate
• Horizontal Line Nodes in Sr2RuO4 Proved by Spin Resonance
• Strain-induced time reversal breaking and half quantum vortices near a putative superconducting tetra-critical point in Sr${}_2$RuO${}_4$
• Neutron scattering studies on spin fluctuations in Sr${}_2$RuO${}_4$
• Multiband mean-field theory of the $d+ig$ superconductivity scenario in Sr${}_2$RuO${}_4$
• $\mu$SR measurements on Sr${}_2$RuO${}_4$ under $⟨110⟩$ uniaxial stress
• Upper Critical Field of Sr${}_2$RuO${}_4$ under In-Plane Uniaxial Pressure
• A review of some new perspectives on the theory of superconducting Sr${}_2$RuO${}_4$
• Reconciling $\pi$ phase shift in Josephson junction experiments with even-parity superconductivity in Sr${}_2$RuO${}_4$
• Frequency-dependent sensitivity of AC elastocaloric effect measurements explored through analytical and numerical models

Cited by in corpus (11)

• Spontaneous time-reversal symmetry breaking by disorder in superconductors
• Thermodynamic transitions and topology of spin-triplet superconductivity: Application to UTe${}_2$
• $T_c$ and the elastocaloric effect of Sr${}_2$RuO${}_4$ under $⟨110⟩$ uniaxial stress: no indications of transition splitting
• Competition between d-wave superconductivity and magnetism in uniaxially strained Sr2RuO4
• Conditions for orbital selective altermagnetism in Sr${}_2$RuO${}_4$: tight binding model, similarities with cuprates and implications on superconductivity
• Magic angle of Sr${}_2$RuO${}_4$: Optimizing correlation-driven superconductivity
• Elastic Quantum Criticality in Nematics and Altermagnets via the Elasto-Caloric Effect
• Magnetic-field-tuned randomness in inhomogeneous altermagnets
• Polar Kerr Effect in Multiband Spin-Orbit Coupled Superconductors
• Why Scanning Tunneling Microscopy on Sr${}_2$RuO${}_4$ sometimes doesn't see the superconducting gap
• Anisotropic scattering rates in strain-tuned Sr${}_2$RuO${}_4$