Field-induced Berezinskii-Kosterlitz-Thouless transition and string-density plateau in the anisotropic triangular antiferromagnetic Ising model

TL;DR

This study investigates the field-induced Berezinskii-Kosterlitz-Thouless transition in a triangular antiferromagnetic Ising model, accurately estimating the transition point and analyzing the stability of a string-density plateau.

Contribution

It provides a precise estimate of the BKT transition point and explores the stability of the string-density plateau in an anisotropic triangular Ising model.

Findings

Estimated BKT transition point at H_c ≈ 0.523 with high accuracy.

Confirmed the stability of the string-density plateau against incommensurate liquid states.

Validated results using level spectroscopy and density-matrix renormalization-group methods.

Abstract

The field-induced Berezinskii-Kosterlitz-Thouless (BKT) transition in the ground state of the triangular antiferromagnetic Ising model is studied by the level-spectroscopy method. We analyze dimensions of operators around the BKT line, and estimate the BKT point $H_{\rm c}\simeq0.5229\pm0.001$, which is followed by a level-consistency check to demonstrate the accuracy of our estimate. Further we investigate the anisotropic case to clarify the stability of the field-induced string-density plateau against an incommensurate liquid state by the density-matrix renormalization-group method.