Topological phase diagrams of the frustrated Ising ferromagnet

TL;DR

This paper develops a method combining mean-field and renormalization group techniques to predict topological phases in frustrated Ising ferromagnets, revealing complex phase reentrance and topological transitions in magnetic thin films.

Contribution

It introduces a novel approach to identify topological phases in a coarse-grained Ising model with dipolar interactions using microscopic Hamiltonian data.

Findings

Reentrant phase diagrams in weak dipolar regimes.

Identification of anomalous topological transitions.

Potential for discovering new magnetic phases in experiments.

Abstract

The emergence of complex modulated structures in the magnetization pattern of thin films is a well-established experimental phenomenology caused by the frustrating effects of competing interactions. Using a coarse-grained version of the Ising ferromagnet with dipolar interactions, we develop a method that uses the information from the microscopic Hamiltonian to predict the specific topological phases present in the temperature-external magnetic field phase diagram. This is done by the combination of mean-field variational calculations and the renormalization group equations from the classical theory of two-dimensional melting. In this framework, we are able to distinguish when the orientational and translational symmetries are broken, discriminating between the ordered and disordered states of the system for all temperatures and fields. We observe that the reentrance developed by the $H$-$T$ phase diagrams in the regime of weak dipolar interactions is directly related with the appearance of anomalous topological transitions. These results motivate the realization of new experiments on magnetic thin films in order to explore the topological properties of the magnetic textures, allowing to identify new exotic phases in these materials.