Wess-Zumino-Witten Terms in Graphene Landau Levels

TL;DR

This paper explores the theoretical connection between different orderings in graphene Landau levels, revealing Wess-Zumino-Witten terms that suggest deconfined criticality and potential excitonic superfluidity in experiments.

Contribution

It demonstrates the existence of Wess-Zumino-Witten terms between competing orders in graphene Landau levels, linking quantum fluctuations to deconfined critical theories.

Findings

Presence of Wess-Zumino-Witten terms between orders

Implications for excitonic superfluidity in bilayer graphene

Quantum fluctuations described by deconfined critical theories

Abstract

We consider the interplay between the antiferromagnetic and Kekul\'e valence bond solid orderings in the zero energy Landau levels of neutral monolayer and bilayer graphene. We establish the presence of Wess-Zumino-Witten terms between these orders: this implies that their quantum fluctuations are described by the deconfined critical theories of quantum spin systems. We present implications for experiments, including the possible presence of excitonic superfluidity in bilayer graphene.