Nature of quantum spin liquids of the S=1/2 Heisenberg antiferromagnet on the triangular lattice: A parallel DMRG study

TL;DR

This study uses advanced DMRG techniques to analyze the quantum spin liquid phases of the spin-1/2 Heisenberg antiferromagnet on a triangular lattice, revealing gapped and gapless QSL states with specific correlation properties.

Contribution

It introduces a parallel DMRG approach with SU(2) symmetry to accurately characterize QSL phases on large cylinders, identifying new critical gapless states with specific correlation behaviors.

Findings

The J1-J2 model's QSL phase is gapped with short-range correlations.

Adding J3 interaction leads to a critical gapless QSL with power-law dimer correlations.

Both spin-spin and chiral correlations are short-ranged in the studied phases.

Abstract

We study the ground-state properties of the quantum spin liquid (QSL) phases of the spin-$1/2$ antiferromagnetic Heisenberg model on the triangular lattice with nearest- ($J_1$), next-nearest- ($J_2$), and third-neighbor ($J_3$) interactions by using density-matrix renormalization group (DMRG) method. By combining parallel DMRG with $SU(2)$ spin rotational symmetry, we are able to obtain accurate results on large cylinders with length up to $L_x=48$ and circumference $L_y=6 - 12$. Our results suggest that the QSL phase of the $J_1$-$J_2$ Heisenberg model is gapped which is characterized by the absence of gapless mode, short-range spin-spin and dimer-dimer correlations. In the presence of $J_3$ interaction, we find that a new critical QSL with a single gapless mode emerges. While both spin-spin and scalar chiral-chiral correlations are short-ranged, dimer-dimer correlations are quasi-long-ranged which decays as a power-law at long distances.