Symmetry of the superconducting order parameter in frustrated systems determined by the spatial anisotropy of spin correlations

TL;DR

This paper investigates how spatial anisotropy in spin correlations influences the symmetry of the superconducting order parameter in frustrated systems, using RVB theory on an anisotropic triangular lattice.

Contribution

It demonstrates that varying frustration alters the spin correlation wavevector and consequently changes the superconducting symmetry, linking theory to organic superconductor experiments.

Findings

Spin correlation wavevector varies with frustration.

Superconducting symmetry depends on spin correlation anisotropy.

Applicable to quasi-2D organic superconductors.

Abstract

We study the resonating valence bond (RVB) theory of the Hubbard-Heisenberg model on the half-filled anisotropic triangular lattice. Varying the frustration changes the wavevector of maximum spin correlation in the Mott insulating phase. This, in turn, changes the symmetry of the superconducting state, that occurs at the boundary of the Mott insulating phase. We propose that this physics is realised in several families of quasi-two-dimensional organic superconductors.