Deconfinement criticality for the spatially anisotropic triangular antiferromagnet with the ring exchange

TL;DR

This study uses numerical diagonalization to explore phase transitions in an anisotropic triangular antiferromagnet, revealing a continuous deconfinement-criticality transition influenced by ring exchange, aligning with theories related to high-temperature superconductivity.

Contribution

It demonstrates how ring exchange suppresses intermediate phases, enabling a direct, continuous VBS-Neel transition consistent with deconfinement-criticality scenarios.

Findings

Identification of an intermediate phase between VBS and Neel states.

Suppression of the intermediate phase by ring exchange.

Observation of a continuous phase transition with critical exponent ν=0.80(15).

Abstract

The spatially anisotropic triangular antiferromagnet is investigated with the numerical diagonalization method. As the anisotropy varies, the model changes into a variety of systems such as the one-dimensional, triangular, and square-lattice antiferromagnets. Taking into account such a geometrical character, we impose the screw-boundary condition, which interpolates smoothly the one- and two-dimensional lattice structures. Diagonalizing the finite clusters with N=16,20,...,32 spins, we observe an intermediate phase between the VBS and Neel phases. Suppressing the intermediate phase by applying the ring exchange, we realize a direct VBS-Neel transition. The simulation data indicate that the transition is a continuous one with the correlation-length critical exponent \nu=0.80(15). These features are in agreement with the deconfinement-criticality scenario advocated by Senthil and coworkers in the context of the high-temperature superconductivity.