Spin-noise spectroscopy as a tool for probing magnetic order

TL;DR

This paper explores how spin noise spectroscopy can be used as a non-invasive tool to probe magnetic order, phase transitions, and magnon dynamics in ferro- and antiferromagnets through numerical simulations.

Contribution

It demonstrates the potential of ultrafast spin-noise spectroscopy to extract detailed magnetic information from equilibrium spin fluctuations.

Findings

Can determine phase transitions from spin noise spectra

Identifies magnon mode frequencies via noise measurements

Estimates correlation times in magnetic materials

Abstract

Spin noise spectroscopy is a technique to measure magnetization fluctuations, a subject of increasing relevance in ultrafast spintronics. We investigate numerically the equilibrium spin noise of ferro- and antiferromagnets within an atomistic spin model. The aim is to predict the possible outcomes of ultrafast spin-noise spectroscopy measurements and demonstrate what relevant information can be extracted. Specifically, we show how this method can be used to determine phase transitions, frequencies of magnon modes and correlation times.