Superconductivity in Mutual Chern-Simons Gauge Theory

TL;DR

This paper introduces a topological framework for understanding superconductivity in a model with fractionalized electrons, highlighting the role of mutual Chern-Simons gauge fields and topological order parameters.

Contribution

It provides a novel topological characterization of superconductivity in a fractionalization model, replacing traditional descriptions with a gauge-invariant approach.

Findings

Superconductivity is characterized by a topological order parameter linked to a linking number.

A gauge-neutral fermionic mode emerges, resembling a Bogoliubov quasiparticle.

An experimental probe for the topological order parameter is proposed.

Abstract

In this work, we present a topological characterization of superconductivity in a prototype electron fractionalization model for doped Mott insulators. In this model, spinons and holons are coupled via the mutual Chern-Simons gauge fields. We obtain a low-lying effective description of the collective current fluctuations by integrating out the matter fields, which replaces the conventional Ginzburg-Landau action to describe the generalized rigidity of superconductivity. The superconducting phase coherence is essentially characterized by a topological order parameter related to a Gaussian linking number, and an experiment is proposed to probe this topological property. We further show that a gauge-neutral fermionic mode can naturally emerge in this model, which behaves like a Bogoliubov quasiparticle.