High-resolution magnetostriction measurements of the Pauli-limited superconductor Sr2RuO4

Abstract

We performed high-resolution magnetostriction measurements on the Pauli-limited superconductor Sr${}_2$RuO${}_4$ using high-quality single crystals. A first-order superconducting transition, accompanied by pronounced hysteresis, was observed under in-plane magnetic fields, where the relative length change of the sample, $\Delta L/L$, was on the order of $10^{-8}$. To ensure the reliability of the measurements, particular attention was paid to minimizing the influence of magnetic torque, which can significantly affect data under in-plane field configurations, via field-angle-resolved magnetostriction. Within the hysteresis regime, slightly below the Pauli-limited upper critical field, a hump-like anomaly in the magnetostriction coefficient was identified. Furthermore, a characteristic double-peak structure in the field-angle derivative of the magnetostriction provides additional support for this anomaly. Although these findings may reflect a lattice response associated with the emergence of the Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) phase in Sr${}_2$RuO${}_4$, the possibility of a broadened first-order transition cannot be excluded. Notably, this magnetostriction anomaly qualitatively deviates from the FFLO phase boundary suggested by previous NMR measurements, highlighting the necessity for further experimental and theoretical investigations to elucidate the nature of the FFLO state in this material.

arXiv comment7 pages, 7 figures (main text) + 4 pages, 2 figures (Supplemental Material), accepted for publication in J. Phys. Soc. Jpn

References in corpus (36)

• Fulde-Ferrell-Larkin-Ovchinnikov Superconducting State in CeCoIn5
• Fulde-Ferrell-Larkin-Ovchinnikov State in Heavy Fermion Superconductors
• Evaluation of Spin-Triplet Superconductivity in Sr2RuO4
• Pronounced drop of ${}^{17}$O NMR Knight shift in superconducting state of Sr${}_2$RuO${}_4$
• Strong Peak in $T_c$ of Sr${}_2$RuO${}_4$ Under Uniaxial Pressure
• Fermi Surface, Surface States, and Surface Reconstruction in Sr2RuO4
• A polarized neutron-scattering study of the Cooper-pair moment in Sr2RuO4
• Detailed Topography of the Fermi Surface of Sr2RuO4
• Evidence of Andreev bound states as a hallmark of the FFLO phase in $\kappa$-(BEDT-TTF)${}_2$Cu(NCS)${}_2$
• Reduction of the ${}^{17}$O Knight shift in the Superconducting State and the Heat-up Effect by NMR Pulses on Sr${}_2$RuO${}_4$
• First-Order Superconducting Transition of Sr2RuO4
• Evidence for an FFLO state with segmented vortices in the BCS-BEC-crossover superconductor FeSe
• Thermodynamic evidence for the Fulde-Ferrell-Larkin-Ovchinnikov state in the KFe2As2 superconductor
• Superconducting Double Transition and the Upper Critical Field Limit of Sr2RuO4 in Parallel Magnetic Fields
• Reduction of the spin susceptibility in the superconducting state of Sr2RuO4 observed by polarized neutron scattering
• Searching for gap zeros in Sr2RuO4 via field-angle-dependent specific-heat measurement
• A key role of correlation effects in the Lifshitz transition in Sr${}_2$RuO${}_4$
• Calorimetric Measurements of Magnetic-Field-Induced Inhomogeneous Superconductivity Above The Paramagnetic Limit
• Magnetic field induced lattice anomaly inside the superconducting state of CeCoIn${}_5$: evidence of the proposed Fulde-Ferrell-Larkin-Ovchinnikov state
• Angular dependence of the upper critical field of Sr2RuO4
• Sharp magnetization jump at the first-order superconducting transition in Sr2RuO4
• Improved Single-Crystal Growth of Sr${}_2$RuO${}_4$
• The Superconductivity of Sr${}_2$RuO${}_4$ Under $c$-Axis Uniaxial Stress
• Specific-heat evidence of the first-order superconducting transition in Sr2RuO4
• Anisotropy of the Superconducting State in Sr2RuO4
• Detailed study of the ac susceptibility of Sr2RuO4 in oriented magnetic fields
• Quasi-classical determination of the in-plane magnetic field phase diagram of superconducting Sr_2RuO_4
• Multiple superconducting transitions in the Sr3Ru2O7 region of Sr3Ru2O7-Sr2RuO4 eutectic crystals
• Investigation into the Itinerant metamagnetism of Sr3Ru2O7 for the Field Parallel to the Ruthenium Oxygen Planes
• Formation of non-unitary state near the upper-critical field of Sr${}_2$RuO${}_4$
• Field Evolution of the Fulde-Ferrell-Larkin-Ovchinnikov State in a Superconductor with Strong Pauli Effects
• Modulation vector of the Fulde-Ferrell-Larkin-Ovchinnikov state in CeCoIn5 revealed by high-resolution magnetostriction measurements
• Interplay between effective mass anisotropy and Pauli paramagnetic effects in a multiband superconductor--Application to Sr2RuO4--
• In-plane magnetic field phase diagram of superconducting Sr2RuO4
• Microscopic Eilenberger theory of Fulde-Ferrell-Larkin-Ovchinnikov states in the presence of vortices
• Observation of two critical points linked to the high field phase B in CeCu2Si2