Spin Liquid Phase in Anisotropic Triangular Lattice Heisenberg Model: Exact diagonalization and density-matrix renormalization group calculations

TL;DR

This paper uses exact diagonalization and DMRG to identify a spin-liquid phase in an anisotropic triangular lattice Heisenberg model, revealing its stability and characteristics in relation to quantum fluctuations and experimental observations.

Contribution

It provides the first detailed phase diagram showing the persistence of a spin-liquid phase up to a high anisotropic coupling ratio using advanced numerical methods.

Findings

Spin-liquid phase exists in the weak interchain coupling regime.

The phase persists up to a coupling ratio of 0.78.

The phase exhibits exponential decay of spin correlations along the weaker coupling direction.

Abstract

Based on exact diagonalization and density matrix renormalization group (DMRG) method, we show that an anisotropic triangle lattice Heisenberg spin model has three distinct quantum phases. In particular, a spin-liquid phase is present in the weak interchain coupling regime, which is characterized by an exponentially-decaying spin correlator along the weaker coupling direction and a quasi-one-dimensional spin structure factor along the chain direction, in agreement with experiments on the Cs2CuCl4 compounds. In the obtained phase diagram, the spin liquid phase is found to persist up to a relatively large critical anisotropic coupling ratio J'/J=0.78, which is stabilized by strong quantum fluctuations, with a parity symmetry distinct from two magnetic ordered states in the stronger coupling regime.