Layer anti-ferromagnetism on bilayer honeycomb lattice.

Hong-Shuai Tao,Wu-Ming Liu,Heng-Fu Lin,Yao-Hua Chen,Hai-Di Liu

doi:10.1038/srep05367

Abstract

Bilayer honeycomb lattice, with inter-layer tunneling energy, has a parabolic dispersion relation, and the inter-layer hopping can cause the charge imbalance between two sublattices. Here, we investigate the metal-insulator and magnetic phase transitions on the strongly correlated bilayer honeycomb lattice by cellular dynamical mean-field theory combined with continuous time quantum Monte Carlo method. The procedures of magnetic spontaneous symmetry breaking on dimer and non-dimer sites are different, causing a novel phase transition between normal anti-ferromagnet and layer anti-ferromagnet. The whole phase diagrams about the magnetism, temperature, interaction and inter-layer hopping are obtained. Finally, we propose an experimental protocol to observe these phenomena in future optical lattice experiments.

Highlights

IntroductionWe investigate the metal-insulator and magnetic phase transitions on the strongly correlated bilayer honeycomb lattice by cellular dynamical mean-field theory combined with continuous time quantum Monte Carlo method
Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
Previous work mainly focus on the electronic properties of BHL17–24, and the phase diagram for the magnetic phase transition induced by the interaction and dimers are still absent

Summary

Introduction

We investigate the metal-insulator and magnetic phase transitions on the strongly correlated bilayer honeycomb lattice by cellular dynamical mean-field theory combined with continuous time quantum Monte Carlo method. The whole phase diagrams about the magnetism, temperature, interaction and inter-layer hopping are obtained. The dynamical mean-field theory (DMFT) has been proved to be a very useful and effective tool[32,33,34,35], which has made significantly progress as in the study of metal-insulator phase transition. We investigate the finite temperature metal-insulator and magnetic phase transition in strongly correlated bilayer honeycomb lattice (BHL) by combining the cellular dynamical mean-field theory (CDMFT) with continue-time quantum Monte Carlo (CTQMC) method[42]. The nonlocal inter-layer hopping plays an important role on localizing the free election and modifying the spatial distribution of the electron in lattice sites, especially in dimer sites. We have presented the DOS, double occupancy, and fermi surface below, which can be directly detected in future experiments

Methods

Results

Conclusion