Proposal for an Experiment to Test a Theory of High Temperature Superconductors

TL;DR

This paper proposes an experiment to detect symmetry-breaking order parameters in high-temperature superconductors, specifically using angle-resolved photoemission to observe differences in current density for circular polarizations.

Contribution

It introduces a novel experimental approach to test a specific symmetry-breaking prediction in the pseudogap phase of high-temperature superconductors.

Findings

Estimated asymmetry of about 0.1 in underdoped samples

Predicted momentum dependence of the effect

Potential to identify symmetry-breaking in pseudogap phase

Abstract

A theory for the phenomena observed in Copper-Oxide based high temperature superconducting materials derives an elusive time-reversal and rotational symmetry breaking order parameter for the observed pseudogap phase ending at a quantum-critical point near the composition for the highest $T_c$. An experiment is proposed to observe such a symmetry breaking. It is shown that Angle-resolved Photoemission yields a current density which is different for left and right circularly polarized photons. The magnitude of the effect and its momentum dependence is estimated. Barring the presence of domains of the predicted phase an asymmetry of about 0.1 is predicted at low temperatures in moderately underdoped samples.