X-ray natural dichroism and chiral order in underdoped cuprates

TL;DR

This paper explores whether chiral charge order in underdoped cuprates can be detected using x-ray natural circular dichroism, providing insights into the origin of Kerr rotation in the pseudogap phase.

Contribution

It investigates the potential of XNCD to observe chiral charge order in cuprates, considering various stacking configurations along the c-axis.

Findings

Certain charge order types produce detectable XNCD signals

Stacking along the c-axis influences the XNCD response

Chiral order could explain Kerr rotation phenomena

Abstract

The origin of the Kerr rotation observed in the pseudogap phase of cuprates has been the subject of much speculation. Recently, it has been proposed that this rotation might be due to chiral charge order. Here, I investigate whether such order can be observed by x-ray natural circular dichroism (XNCD). Several types of charge order were considered, and they can give rise to an XNCD signal depending on the stacking of the order along the c-axis.