Deconfined criticality for the S=1 spin model on the spatially anisotropic triangular lattice

TL;DR

This study numerically investigates the quantum S=1 spin model on an anisotropic triangular lattice, revealing a continuous phase transition between nematic and VBS phases consistent with deconfined criticality.

Contribution

It demonstrates the existence of a continuous nematic-VBS phase transition with unconventional critical indices in an S=1 model on an anisotropic lattice.

Findings

Continuous phase transition observed with critical exponent ν=0.92(10)

Nematic and VBS phases realized by tuning anisotropy and biquadratic interactions

Use of screw-boundary condition to account for spatial anisotropy

Abstract

The quantum S=1 spin model on the spatially anisotropic triangular lattice is investigated numerically. The nematic and valence-bond-solid (VBS) phases are realized by adjusting the spatial anisotropy and the biquadratic interaction. The phase transition between the nematic and VBS phases is expected to be a continuous one with unconventional critical indices (deconfined criticality). The geometrical character (spatial anisotropy) is taken into account by imposing the screw-boundary condition (Novotny's method). Diagonalizing the finite-size cluster with N \le 20 spins, we observe a clear indication of continuous phase transition. The correlation-length critical exponent is estimated as \nu=0.92(10).