Unconventional superconductivity on the triangular lattice Hubbard model

2013/04/30 by Kuang Shing Chen, Zi Yang Meng, Unjong Yu +3 · 1 citation
Physics and Astronomy · #cond-mat.str-el

paper · pdf · doi:10.1103/physrevb.88.041103

published as Phys. Rev. B 88, 041103(R) (2013) · 5 pages, 4 figures

arxiv created 2013/07/06 · arxiv updated 2013/07/09

Abstract

Using large-scale dynamical cluster quantum Monte Carlo simulations, we explore the unconventional superconductivity in the hole-doped Hubbard model on the triangular lattice. Due to the interplay of electronic correlations, geometric frustration, and Fermi surface topology, we find a doubly degenerate singlet pairing state at an interaction strength close to the bare bandwidth. Such an unconventional superconducting state is mediated by antiferromagnetic spin fluctuations along the Γ-K direction, where the Fermi surface is nested. An exact decomposition of the irreducible particle-particle vertex further confirms the dominant component of the effective pairing interaction comes from the spin channel. Our findings provide support for chiral d +i d superconductivity in water-intercalated sodium cobaltates Na_xCoO₂ ⋅ yH₂O, as well as insight into the superconducting phases of the organic compounds κ-(ET)₂X and Pd(dmit)₂.

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