Variational Monte Carlo Studies of Pairing Symmetry for the t-J Model on a Triangular Lattice

Abstract

As a model of a novel superconductor Na_xCoO_2\cdotyH_2O, a single-band t-J model on a triangular lattice is studied, using a variational Monte Carlo method. We calculate the energies of various superconducting (SC) states, changing the doping rate δand sign of t for small J/|t|. Symmetries of s, d, and d+id (p+ip and f) waves are taken up as candidates for singlet (triplet) pairing. In addition, the possibility of Nagaoka ferromagnetism and inhomogeneous phases is considered. It is revealed that, among the SC states, the d+id wave always has the lowest energy, which result supports previous mean-field studies. There is no possibility of triplet pairing, although the f-wave state becomes stable against a normal state in a special case (δ=0.5 and t<0). For t<0, the complete ferromagnetic state is dominant in a wide range of δand J/|t|, which covers the realistic parameter region of superconductivity.

arXiv comment10 pages, 13 figures

References in corpus (20)

• Long range Neel order in the triangular Heisenberg model
• Superconductivity Phase Diagram of Na(x)CoO(2).1.3H(2)O
• An Electronic Model for $Co{O}_2$ layer based systems: Chiral RVB metal and Superconductivity
• Projected Wavefunctions and High Temperature Superconductivity
• Superconductivity in CoO${}_2$ Layers and the Resonating Valence Bond Mean Field Theory of the Triangular Lattice t-J model
• Unconventional Superconductivity and Electron Correlations in Cobalt Oxyhydrate Na${}_{0.35}$CoO${}_2$$\cdot y$H${}_2$O
• Doped t-J Model on a Triangular Lattice: Possible Application to Na${}_x$CoO${}_2\cdot y$H${}_2$0 and Na${}_{1-x}$TiO${}_2$
• Phase Diagram and Pairing Symmetry of the Two-Dimensional t-J Model by a Variation Theory
• Quantum Critical Behavior and Possible Triplet Superconductivity in Electron Doped CoO2 Sheets
• Superconducting states in frustrating t-J model: A model connecting high-$T_c$ cuprates, organic conductors and Na${}_x$CoO${}_2$
• Superconductivity Near Phase Separation in Models of Correlated Electrons
• Circuit theory of unconventional superconductor junctions
• Theory of charge transport in diffusive normal metal / unconventional singlet superconductor contacts
• Unconventional Superconductivity and Nearly Ferromagnetic Spin Fluctuations in Na${}_x$CoO${}_2$$\cdot y$H${}_2$O
• Possible spin triplet superconductivity in Na${}_x$CoO${}_2\cdot y$H${}_2$0
• Crossover of superconducting properties and kinetic-energy gain in two-dimensional Hubbard model
• Lattice dependence of saturated ferromagnetism in the Hubbard model
• Superconductivity in Na_xCoO_2yH_2O by charge fluctuation
• 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

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