Applications for ultimate spatial resolution in LASER based $\mu$-ARPES: A FeSe case study

TL;DR

This study demonstrates the use of laser-based micro-ARPES to achieve high spatial resolution in imaging domain structures within FeSe, revealing domain size and distribution with minimal cross-contamination.

Contribution

It introduces a method combining laser ARPES with spatial control to analyze domain populations at a micrometer scale in FeSe.

Findings

Domain population varies on a scale of a few 10 μm

Single domain size is constrained to less than 5 μm

Method reduces spectral cross contamination in domain analysis

Abstract

Combining Angle resolved photoelectron spectroscopy (ARPES) and a $\mu$-focused Laser, we have performed scanning ARPES microscopy measurements of the domain population within the nematic phase of FeSe single crystals. We are able to demonstrate a variation of the domain population density on a scale of a few 10 $\mu$m while constraining the upper limit of the single domain size to less than 5 $\mu m$. This experiment serves as a demonstration of how combining the advantages of high resolution Laser ARPES and an ultimate control over the spatial dimension can improve investigations of materials by reducing the cross contamination of spectral features of different domains.