Nematic and chiral orders for planar spins on triangular lattice

TL;DR

This paper introduces a modified antiferromagnetic XY model on a triangular lattice to explore the coexistence of chiral and nematic orders, revealing a chiral-nematic phase with dominant bi-quadratic interactions.

Contribution

It presents a new variant of the XY model with bi-quadratic interactions, demonstrating the existence of a chiral-nematic phase and analyzing its phase diagram and critical properties.

Findings

Existence of a chiral-nematic phase without magnetic order

A large temperature window for nematic and chiral coexistence

Phase diagram and critical properties derived via Monte Carlo simulations

Abstract

We propose a variant of the antiferromagnetic XY model on the triangular lattice to study the interplay between the chiral and nematic orders in addition to the magnetic order. The model has a significant bi-quadratic interaction of the planar spins. When the bi-quadratic exchange energy dominates, a large temperature window is shown to exist over which the nematic and the chiral orders co-exist without the magnetic order, thus defining a chiral-nematic state. The phase diagram of the model and some of its critical properties are derived by means of the Monte Carlo simulation.