Possible unconventional superconductivity in Na${}_x$CoO${}_2$yH${}_2$O probed by $\mu$SR

Abstract

The superconducting property of recently discovered sodium cobalt oxyhydrate, Na${}_{0.35}$CoO${}_2$1.3H${}_2$O ($T_c=4.5$ K), has been studied by means of muon spin rotation/relaxation ($\mu$SR) down to 2 K. It was found that the zero-field muon spin relaxation rate is independent of the temperature, indicating that no static magnetism appears in this compound, at least above 2 K. The result also provides evidence against the breakdown of time-reversal symmetry for the superconducting order parameter. Meanwhile, the muon Knight shift at 60 kOe shows no obvious reduction below $T_c$, suggesting that the local spin susceptibility is preserved upon a superconducting transition. Considering these observations, possible unconventional superconductivity of Na${}_{0.35}$CoO${}_2$1.3H${}_2$O is discussed.

9 pages, 5 figures

References in corpus (13)

• Time-Reversal Symmetry Breaking Superconductivity in Sr2RuO4
• Superconductivity Phase Diagram of Na(x)CoO(2).1.3H(2)O
• Time-Reversal Symmetry-Breaking Superconductivity in Heavy Fermion PrOs4Sb12 detected by Muon Spin Relaxation
• An Electronic Model for $Co{O}_2$ layer based systems: Chiral RVB metal and Superconductivity
• Unconventional Superconductivity and Electron Correlations in Cobalt Oxyhydrate Na${}_{0.35}$CoO${}_2$$\cdot y$H${}_2$O
• Doped t-J Model on a Triangular Lattice: Possible Application to Na${}_x$CoO${}_2\cdot y$H${}_2$0 and Na${}_{1-x}$TiO${}_2$
• Superconducting states in frustrating t-J model: A model connecting high-$T_c$ cuprates, organic conductors and Na${}_x$CoO${}_2$
• Instabilities of interacting electrons on the triangular lattice
• Unconventional Superconductivity and Nearly Ferromagnetic Spin Fluctuations in Na${}_x$CoO${}_2$$\cdot y$H${}_2$O
• Possible spin triplet superconductivity in Na${}_x$CoO${}_2\cdot y$H${}_2$0
• Unconventional Upper- and Lower-Critical Fields and Normal-State Magnetic Susceptibility of the Novel Superconducting Compound $N{a}_{0.35}Co{O}_2\cdot 1.3H_{2}O$
• 59Co-NMR Knight Shift of the Superconducting NaxCoO2.yH2O
• Possibility of f-wave spin-triplet superconductivity in the CoO superconductor: a case study on a 2D triangular lattice in the repulsive Hubbard model

Cited by in corpus (24)

• Unconventional Superconductivity
• Magnetic ordering and spin waves in $\mathbf{N}{\mathbf{a}}_{0.82}\mathbf{Co}{\mathbf{O}}_2$
• Ferromagnetic fluctuation and possible triplet superconductivity in Na_xCoO_2*yH_2O: Fluctuation-exchange study of multi-orbital Hubbard model
• A critical assessment of the pairing symmetry in NaxCoO2.yH2O
• Multi-orbital analysis on the Superconductivity in Na_{x}CoO_{2} \cdot y H_{2}O
• Low-Temperature and High-Energy-Resolution Laser Photoemission Spectroscopy
• Nodal $d+id$ pairing and topological phases on the triangular lattice: unconventional superconducting state of Na${}_x$CoO${}_2\cdot y$H${}_2$O
• Competition between singlet and triplet pairings in Na_xCoO_2 yH_2O
• Possible Spin-triplet Superconductivity in NaxCoO2yH2O - 59Co NMR Study
• Ferromagnetic and triplet-pairing instabilities controlled by the trigonal distortion of the CoO_6 octahedra in Na_xCoO_2*yH_2O
• Shubnikov de Haas effect in the metallic state of Na${}_{0.3}$CoO${}_2$
• Laser-excited ultrahigh-resolution photoemission spectroscopy of NaxCoO2.yH2O:Evidence for pseudogap formation
• Spin gaps and magnetic structure of NaxCoO2
• Anisotropic Behavior of Knight Shift in Superconducting State of Na_xCoO_2yH_2O
• Role of spin-orbit coupling on the spin triplet pairing in Na_{x}CoO_{2}yH_{2}O I: d-vector under zero magnetic field
• CoO2-Layer-Thickness Dependence of Magnetic Properties and Possible Two Different Superconducting States in NaxCoO2.yH2O
• Cooperative effect of phonons and electronic correlations for superconductivity in cobaltates
• Role of spin-orbit coupling on the spin triplet pairing in Na_{x}CoO_{2}yH_{2}O II: Multiple phase diagram under the magnetic field
• Electron-phonon interaction dressed by electronic correlations near charge ordering as the origin for superconductivity in cobaltates
• Dynamical magnetic susceptibility in the lamellar cobaltate superconductor Na_xCoO_2$\cdot y$H_2O
• Numerical study of magnetic and pairing correlation in bilayer triangular lattice
• Identifying the pairing symmetry in sodium cobalt oxide by Andreev edge states
• Unconventional superconductivity in NaxCoO2 yH2O
• One-particle spectral properties of the t-J-$V$ model on the triangular lattice near charge order