Bragg glass signatures in Pd$_x$ErTe$_3$ with X-ray diffraction Temperature Clustering (X-TEC)

TL;DR

This study provides experimental evidence for the Bragg glass phase in disordered PdxErTe3 using X-ray diffraction and machine learning, revealing diverging correlation lengths and advancing understanding of disorder in charge density waves.

Contribution

It introduces X-ray temperature clustering (X-TEC), a machine learning method, and a high-throughput measure called peak spread to detect Bragg glass order in disordered materials.

Findings

Evidence of diverging correlation length in PdxErTe3

Identification of Bragg glass phase in charge density waves

Introduction of peak spread as a new analysis measure

Abstract

The Bragg glass phase is a nearly perfect crystal with glassy features predicted to occur in vortex lattices and charge density wave systems in the presence of disorder. Detecting it has been challenging despite its sharp theoretical definition in terms of diverging correlation lengths. Here, we present evidence supporting a Bragg glass phase in the systematically disordered charge density wave material PdxErTe3. We do this using comprehensive x-ray data and a machine learning analysis tool called X-ray temperature clustering, or X-TEC. We establish a diverging correlation length in samples with moderate intercalation over a wide temperature range. To enable this analysis, we introduced a high-throughput measure of inverse correlation length that we call peak spread. The detection of Bragg glass order and the resulting phase diagram advance our understanding of the complex interplay between disorder and fluctuations significantly. Moreover, the use of our analysis technique to target fluctuations through a high-throughput measure of peak spread can revolutionize the study of fluctuations in scattering experiments.