Phase diagram of the dipolar Ising ferromagnet on a kagome lattice

TL;DR

This paper maps the phase diagram of a 2D dipolar Ising ferromagnet on a kagome lattice, revealing multiple stripe and bubble phases, and transitions between ordered and disordered states using advanced Monte Carlo simulations.

Contribution

It provides the first detailed phase diagram of the dipolar Ising model on a kagome lattice, identifying novel stripe and bubble phases and their transitions.

Findings

Identification of two stripe phases at low fields

Discovery of two bubble phases at high fields

Existence of disordered phases between ordered phases

Abstract

We study the field--temperature phase diagram of the two-dimensional dipolar Ising ferromagnet on a kagome lattice with a specific ratio between the exchange and dipolar constants, $\delta = 1$. Using the stochastic cutoff (SCO) $O(N)$ Monte Carlo method, we calculated order parameters for stripe and bubble phases and other thermodynamical quantities. We find two kinds of stripe phases at low fields, where the arrangement of the branch spins neighboring the stripe frame varies, and two bubble phases at high fields, in which three-spin domains (bubbles) form a regular triangular lattice but the triangular array of bubbles changes on a kagome lattice. We also find that with increasing the field, there exist a disordered phase between the stripe and bubble phases and between the two bubble phases. We discuss the details of the features of these phases and phase transitions.