On the SO(5) Effective Field Theory of High T_c Superconductors

TL;DR

This paper develops a systematic low-energy effective field theory for the SO(5) model of high-temperature superconductors, enabling predictions of observable relations based on approximate symmetry considerations.

Contribution

It constructs the first low-energy effective theory for the SO(5) model, allowing systematic expansion and model-independent predictions of physical observables.

Findings

Predicts relations among low-energy observables due to approximate SO(5) symmetry.

Provides a framework for systematic expansion in symmetry-breaking interactions.

Enables model-independent tests of the SO(5) theory in experiments.

Abstract

We construct the low-energy effective theory for the SO(5) model of high-T_c superconductivity, recently proposed by S.C. Zhang (cond-mat/9610140). This permits us to develop a systematic expansion for low-energy observables in powers of the small symmetry-breaking interactions. The approximate SO(5) symmetry predicts relations amongst these observables, which are model-independent consequences of Zhang's proposed symmetry-breaking pattern.