Unveiling Antiferromagnetic Resonance: A Comprehensive Analysis via the Self-Consistent Harmonic Approximation

TL;DR

This paper applies the Self-Consistent Harmonic Approximation to analyze antiferromagnetic resonance, providing a comprehensive theoretical framework that aligns well with experimental data and enhances understanding of spin dynamics near phase transitions.

Contribution

It extends the SCHA method to antiferromagnetic models, offering a detailed analysis of AFMR in both AF and SF phases with quantum and semiclassical insights.

Findings

SCHA accurately describes AFMR characteristics near transition temperatures.

The approach aligns well with experimental and theoretical data.

Magnetization precession dynamics are effectively modeled using coherent states.

Abstract

The Self-Consistent Harmonic Approximation (SCHA) has demonstrated efficacy in discerning phase transitions and, more recently, in elucidating coherent phenomena within ferromagnetic systems. However, a notable gap in understanding arises when extending this framework to antiferromagnetic models. In this investigation, we employ the SCHA formalism to conduct an in-depth exploration of the Antiferromagnetic Resonance (AFMR) within both Antiferromagnetic (AF) and Spin-Flop (SF) phases. Our analysis includes thermodynamic considerations from both semiclassical and quantum perspectives, with comparisons drawn against contemporary experimental and theoretical data. By incorporating a treatment utilizing coherent states, we investigate the dynamics of magnetization precession, a fundamental aspect in comprehending various spintronic experiments. Notably, the SCHA demonstrates excellent agreement with existing literature, showcasing its simplicity and efficiency in describing AFMR characteristics, even close to the transition temperature.