A Snapshot Review -- Fluctuations in Quantum Materials: From Skyrmions to Superconductivity

TL;DR

This paper introduces a new x-ray technique based on fluctuation analysis to explore quantum materials, offering insights into their fundamental properties and potential for discovering new physics.

Contribution

It presents a novel x-ray method utilizing fluctuation-dissipation relations to study quantum materials, expanding the experimental toolkit for uncovering new physical phenomena.

Findings

Initial results on a topological chiral magnet demonstrate the method's effectiveness.

The technique enables exploration of uncharted phase space regions.

Future plans include applying the method to unconventional superconductors.

Abstract

By measuring a linear response function directly, such as the dynamic susceptibility, one can understand fundamental material properties. However, a fresh perspective can be offered by studying fluctuations. This can be related back to the dynamic susceptibility through the fluctuation-dissipation theorem, which relates the fluctuations in a system to its response, an alternate route to access the physics of a material. Here, we describe a new x-ray tool for material characterization that will offer an opportunity to uncover new physics in quantum materials using this theorem. We provide details of the method and discuss the requisite analysis techniques in order to capitalize on the potential to explore an uncharted region of phase space. This is followed by recent results on a topological chiral magnet, together with a discussion of current work in progress. We provide a perspective on future measurements planned for work in unconventional superconductivity.