Interrelation of Superconducting and Antiferromagnetic Gaps in High-Tc Compounds: a Test Case for a Microscopic Theory

TL;DR

This paper demonstrates that a projected SO(5) theory can microscopically explain the observed correlation between antiferromagnetic and superconducting gaps in high-Tc compounds, unifying these phenomena under a common symmetry framework.

Contribution

It introduces a microscopic mechanism based on projected SO(5) theory that accurately describes the relationship between antiferromagnetic and superconducting gaps in high-Tc materials.

Findings

The theory accounts for the dispersion of the gaps.

It explains the order of magnitude difference between the gaps.

The model matches ARPES data on gap modulation.

Abstract

Recent angle resolved photoemission (ARPES) data, which found evidence for a d-wave-like modulation of the antiferromagnetic gap, suggest an intimate interrelation between the antiferromagnetic insulator and the superconductor with its d-wave gap. This poses a new challenge to microscopic descriptions, which should account for this correlation between, at first sight, very different states of matter. Here, we propose a microscopic mechanism which provides a definite correlation between these two different gap structures: it is shown that a projected SO(5) theory, which aims at unifying antiferromagnetism and d-wave superconductivity via a common symmetry principle while explicitly taking the Mott-Hubbard gap into account, correctly describes the observed gap characteristics. Specifically, it accounts for both the dispersion and the order of magnitude difference between the antiferromagnetic gap modulation and the superconducting gap.