Phase diagram of low-dimensional antiferromagnets with competing order parameters: A Ginzburg-Landau-theory approach

TL;DR

This paper uses a Ginzburg-Landau model to analyze the phase diagram of low-dimensional antiferromagnets with competing order parameters, successfully explaining experimental observations and predicting angular dependencies of spin-reorientation transitions.

Contribution

It introduces a Ginzburg-Landau theoretical framework to describe complex phase behavior in antiferromagnets with competing orders, validated on a quasi-1D material.

Findings

Accurately describes magnetization and phase transitions in BaCu_2Si_2O_7

Predicts unusual angular dependence of spin-reorientation transitions

Provides a comprehensive phase diagram for low-dimensional antiferromagnets

Abstract

We present a detailed analysis of the phase diagram of antiferromagnets with competing exchange-driven and field-induced order parameters. By using the quasi-1D antiferromagnet BaCu_2Si_2O_7 as a test case, we demonstrate that a model based on a Ginzburg-Landau type of approach provides an adequate description of both the magnetization process and of the phase diagram. The developed model not only accounts correctly for the observed spin-reorientation transitions, but it predicts also their unusual angular dependence.