Field-induced QCD3 -Chern-Simons quantum criticalities in Kitaev materials

Liujun Zou,Yin-Chen He

doi:10.1103/physrevresearch.2.013072

Abstract

Kitaev materials are promising for realizing exotic quantum spin liquid phases, such as a non-Abelian chiral spin liquid. Motivated by recent experiments in these materials, we theoretically study the novel field-induced quantum phase transitions from the non-Abelian chiral spin liquid to the symmetry-broken zigzag phase and to the trivial polarized state. Utilizing the recently developed dualities of gauge theories, we find these transitions can be described by critical bosons or gapless fermions coupled to emergent non-Abelian gauge fields, and the critical theories are of the type of a QCD$_3$-Chern-Simons theory. We propose that all these exotic quantum phase transitions can potentially be direct and continuous in Kitaev materials, and we present sound evidence for this proposal. Therefore, besides being systems with intriguing quantum magnetism, Kitaev materials may also serve as table-top experimental platforms to study the interesting dynamics of emergent strongly interacting quarks and gluons in $2+1$ dimensions.

Highlights

Understanding the universal properties of quantum phases and quantum phase transitions is one of the central goals of physics
Utilizing the recently developed dualities of gauge theories, we find these transitions can be described by critical bosons or gapless fermions coupled to emergent non-Abelian gauge fields, and the critical theories are of the type of a QCD3-Chern-Simons theory
Motivated by the recent theoretical and experimental progress in the research on Kitaev materials, we study novel field-induced quantum phase transitions in these materials

Summary

INTRODUCTION

Understanding the universal properties of quantum phases and quantum phase transitions is one of the central goals of physics. There is some subtlety in interpreting this experiment [39,40,41], and the results therein need to be confirmed by further studies, this discovery has triggered great excitement These experimental results suggest that α-RuCl3 exhibits only three phases upon increasing the external magnetic field, namely, the zigzag order, the ITO, and the trivially polarized state [38]. II, we first review the global symmetries of some representative Kitaev materials, including α-RuCl3, Na2IrO3, etc The appendices contain various technical details, some of which present powerful methods that can be adopted to study various related problems

SYMMETRIES OF THE MATERIALS AND MODELS

QCD3-CHERN-SIMONS QUANTUM CRITICALITIES

Topological aspects and bosonic critical theories

Symmetry properties and dual-fermionic theories

EXPERIMENTAL SIGNATURES

SUMMARY AND DISCUSSION