Detecting Dichroism in Angle Resolved Photoemission

TL;DR

This paper generalizes the theory of dichroism detection in angle-resolved photoemission to account for weak mirror plane symmetry violations, aiding the study of time-reversal violation in cuprate pseudogap phases.

Contribution

It extends previous models by incorporating weak mirror symmetry violations, providing a more comprehensive framework for dichroism analysis in complex materials.

Findings

The theory now accounts for superstructure-induced mirror symmetry breaking.

Dichroism signals can be interpreted even with weak symmetry violations.

Supports experimental detection of time-reversal violation in cuprates.

Abstract

Recently, the time-reversal violation predicted for the pseudogap phase of the cuprates, which was observed by dichroism experiments using Angle-Resolved Photoemission has also been observed by polarized neutron diffraction. Earlier derivation of dichroism in angle resolved photoemission due to time-reversal violation relied on existence of mirror planes in the crystal. Here the theory of the effect is generalized to the case that mirror plane symmetry is weakly violated due to perturbing potentials such as a superstructure.